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APPENDIX I THE SI SYSTEM AND SI UNITS FOR RADIOMETRY AND PHOTOMETRY SI BASE UNITS BASE QUANTITY NAME SYMBOL length meter m mass kilogram kg time second s electric current ampere A thermodynamic temperature kelVin K amount of substance mole mol luminous intensity candela cd SELECTED SI DERIVED UNITS QUANTITY NAME SYMBOL EQUIVALENT plane angle radian rad solid angle steradian sr energy joule J Nm power watt W Js 1 frequency hertz HZ s 1 electric charge coulomb C As luminous flux lumen lm cdsr illuminance luX lX lmm 2 luminance candela per square meter cdm 2 lmm 2 sr 1 radiant intensity watt p er steradian Wsr radiance watt per square meter steradian Wmzsr SI PR EFIXES Factor Prefix Symbol Factor Prefix Symbol 1024 yotta Y 10 1 deci d 1021 zetta Z 10 2 centi c 1018 exa E 10 3 milli m 1015 peta P 10 6 micro p 1012 tera T 10 9 nano n 109 giga G 10 12 pico p 106 mega M 10 15 femto f 108 kilo k 10 18 atto a 102 hecto h 10 21 zepto Z 101 deka d 10 24 yocto y Complete SI information is available on the World Wide Web at wwwbipmfr and at physicsnistgovPubsSP8I1SP811html The following tables show radiometric and photometric quantities and symbols definitions and units RADIOMETRIC QUANTITIES QUANTITY SYMBOL DEFINITION UNITS Radiant energy Q joule J Radiant power flux d dQdt watt W Radiant intensity I dQDda wattsr Radiant eXitance M dQDdA wattm2 Irradiance E dQDdA wattm2 Radiance L dZQDdA cosG dog wattm2sr t time s n 2 solid angle sr A 2 area m2 PHOTON QUANTITIES QUANTITY SYMBOL DEFINITION UNITS Photon power flux QDq dndt s Photon intensity I dnda srs Photon eXitance M dndA m2s Photon irradiance Eq dndA m2s Photon radiance Lq d2ndA cosG doa m2srs n photon number SPECTRAL QUANTITIES are derivative per unit wavelength with the additional dimension m l and are indicated by a subscript A eg spectral radiance L A with units VVm 3 sr l Nonspectral quantities that are wavelengthdependant are indicated as A eg transmission 111 PHOTOMETRY is the measurement of light optical radiant energy as above but weighted by the response function of the human eye The symbols used are the same as radiometric quantities with the subscript v for visual added QUANTITY SYMBOL UNITS Luminous Power QDV Lumen lm Luminous EXitance MV lm m2 Luminous Incidance EV lm m2 Luminous Intensity SI base unit IV lm sr candela Luminance LV lm m2sr candela m2 APPENDIX II PHYSICAL CONSTANTS CONVERSION FACTORS AND OTHER USEFUL QUANTITIES Relative Quantity Symbol Value Units uncertainty Speed of light vacuum 0 Co 299 792 458 m s1 exact Permeability of vacuum 0 41tgtlt10 7 N A 2 exact Permittivity of vacuum 80 1uoc2 8854 187 gtlt10 12 F Hr1 exact Planck constant h 6626 068 76 52gtlt10 34 J s 78gtlt10 8 Electronic charge q 2 1602 176 462 63gtlt10 19 C 39gtlt10 8 Boltzmann constant k 1380 6503 24gtlt10 23 J K 1 17gtlt10 6 Boltzmann constant k 8617 342 15gtlt10 5 eV K 1 17gtlt10 6 StefanBoltzmann constant a 5670 400 40gtlt10 8 W Hr2 K 4 70gtlt10 6 First radiation constant 2nhc2 01 3741 771 07 29gtlt10 16 W m2 78gtlt10 8 First radiation constant for LA 01L 1191 042 722 93gtlt 10 16 W In2 SF1 78gtlt10 8 Second radiation constant 02 1438 7752 25gtlt10 2 m K 17gtlt10 6 Wien displacement law constant b 2897 7686 51gtlt10 S m K 17gtlt10 6 These are the 1998 CODATA recommended values of the fundamental physical constants Adapted in part from PJ Mohr amp BN Taylor The Fundamental Physical Constants J Phys Chem Ref Data 28 1713 1999 and Rev Mod Phys 72 351 2000 These constants are also available in Physics Today 54 Part 2 BG6 2001 reprinted yearly and from httQthsicsnistg0Uconstants Here are some useful conversion factors he 2 1986 445gtlt1025 Jm 1986 445gtlt1019 Jum 1986 445gtlt1016 Jnm hcq 123984 eVum kTq 0025852 V at 300K 1eV 1602 176 462x1019J 1AU 1495gtlt1011 m AmaxTZ C24965 114 23 APPENDIX III AN ANTIQUARIANS GARDEN of SANE aid OUTRAGEOUS TERMINOLOGY Fexhaps the most dlfheult tash lh both teachlng ahd leamlhg about ladlometly ahd photometxy ls lealmhg ahd eohveylhg ah applopllate ahd sehslble system of symbols unlts ahd nomenclatuze SUN Thls can be a fozmldable tash because of the enoxmous extent of these found 1n the htezatuxe I have attempted to be eohslsteht Wlth the eulleht 1986 accepted unlts lh thls text and have addzessed the sltuatloh Wlth legald to lhtehslty as well The fo owlng ls aeolleetloh of texms sysbols ahd unlts that l have gathezed Wlth httle effoxt Fexhaps you can add some mole to thls hst some ale st lcuuent ahdsome alelohg obsolete UNDER CONSTRUCTION PHOTOMETRY Fexhaps lh ho selehtlfle held ls the language mole obtuse thah lh photometxy Thls ls lh Iazge measuxe because of the toxtuous path of the development of sultable standazds LU39MINOUS INTENSITY The S I base unlt of Iumlnous lntenslty ls the candeIa ed IEougle deelmale 102 ed IEougle nouVeIle ed llhtematlohaleahdle 101937cd 1 new eahdle 1 ed Icazce110 ed ICazceI unlt 9 79613 ed IHefnexkezze o 903 ed Ivloue 20 4cd IFentene eahdle 1 ed IEnghsh spexm eahdle 1 ed LU39MINOUS POWER The dellved SI unlt oflumlnous ux ls the lumen 1m edesl ILLUMINAN CE The derived 81 unit of illuminance is the luX 1X 2 lmm2 1 footcandle fc or ftc 1 lumen per square foot 1 luX 1X 2 1 lumen per square meter 2 1 metercandle 1 phot ph 1 lumen per square centimeter 104 lX 1 milliphot mph 2 10 3 lmcm2 1 nox 1 milliluX 10 3 luX 1 seamile candle 1 cd 1 nautical mile 6080 ft 29X10 7 lX Luminosity L lumenft 2 Pharosage lumenm12 LUMINANCE The derived 81 unit of luminance is the nit cdm2 1 nit 1 candela per m2 11 apostilb 02919 footlambert 1 stilb sb 1 candela per cm2 1 nit 104 BougieHectometreCarre NOTE Several luminance units are related to the illuminance units by assuming a perfect p 1 diffuse lambertian reflector This simplification leads to 1 footcandle of illumination 3 1 footlambert of luminance 1 lambert 1 lumen per cm2 111 candela per cm2 1 footlambert ftL 111 candela per ft2 1 apostilb asb 111 candela per n12 2 111 nit 1 skot 10393 111 candela per m2 10 S apostilb 1 millilambert m 1 footlambert 1 equivalent phot 1 lambert 1 equivalent luX 1 blondel 1 apostilb 1 equivalent footcandle 1 footlambert LUMINOUS ENERGY The derived 81 unit of luminous energy is the talbot lm sec 1 talbot 107 lumergs cgs 107 erg 1 wattsec Phos lumensec 1 lightwatt 1V71 lumen 2 Km lumen 683 at AP 555 nm Pharos lumen Helios blondel Heliosent blondelm11 Radiant heliosent path radiance hershelm391 luminous efficiency is luminous flux radiant flux luminous efficacy is luminous flux electrical input power mechanical equivalent of light is 1683 wattslumen VISION RESEARCH troland retinal illuminance produced by luminance of 1 cdm2 if entrance pupil of eye is 1 m2 corrected for StilesCrawford effect formerly called the photon troland also defined as the external illuminance that produces retinal illumination of 0002 luX ULTRAVIOLET Eviton erythemal effectiveness equivalent to 10 microwatts 2967nm 1 Finsen 1 Evitoncm2 1 erythemal watt 2 105 Evitons 1 EU 2 1 Eviton 1 erytheme floren UV fluX equivalent to 1 mW between 320 and 400 nm bactericidal microwatt weighted by bactericidal action spectrum ultraviolet microwatt or UV watt evaluated at 2537 nm MPE minimum perceptible erythema 0025 erythemalwattcm2 1 MPE 2500 finsens 1MPE 25gtlt105 ergcm2 2967 nm 1 MED minimum erythemal dose 2 ASTRONOMY 1 Jansky Jy 10 26 VVm zHZ 1 spectral irradiance IWcmzpm 3X10167t2 Jy 1 solar flux unit sfu 104 Jy 1 My 2 1509gtlt10 S keV cm 2s 1 keV 1 1 Jy 242gtlt10 6 erg cm 2 s 1 keV 1 visual magnitude zero 2 265gtlt10 6 luX outside atmosphere IR Handbook p 323 visual magnitude zero 2 254gtlt10 6 luX outside atmosphere Radiometry and photometry in astronomy hotel04 ausyssepauschcompradfaq html visual magnitude zero 2 209gtlt10 6 luX outside atmosphere Optronic Laboratories 1 rayleigh 106 photonscm 2s 1 1 rayleigh 1411gtlt106 photonscm 2s 1sr 1 1 Sm 123gtlt10 12 Wcmzsrum 055 pm equivalent to the number of 10th magnitude stars per square degree 1 Sm 1899gtlt106 photonsscm2srpm 055 pm COLOR APPEARANCE reciprocal megakelvin lIK 1 106TC where TC is color temperature also known as mirek or mired microreciprocal Kelvin or microreciprocal degree MISCELLANEOUS 1 microeinstein HE 6022X1017 photons 1 micromole angstrom obsolete unit of wavelength 2 10mm Kayser waves per centimeter gillette measure of laser energy sufficient to penetrate one standard razor blade micro ick unit of spectral radiance uVVcm zsr lum 1 Spectral lamprosity young per watt Lamprosity y youngs per radiated watt Actance lumens per input watt Radiant phos 2 exposure Wsec Radiant helios radiance hershel following are CIE 1068 PPFD photosynthetic photon ux density measured in mol m 2 sec1 SPPFD spherical photosynthetic photon ux density measured in mol m 2 sec1 PAP photosynthetically active photons measured in molm 2 SPAP spherical photosynthetically active photons measured in molm 2 Irradiation radiant pharosage radiant incidance W m 2 Radiosity radiant pharosage radiant eXitance Wm z Phengosage spectral pharosage Radiant pharos radiant power W 1 Wm2 2 0317 BTUftZhr 1 langley 1 gmcalcm2 APPENDIX IV SOLID ANGLE RELATIONSHIPS 9 deg 69 rad a sr Q sr W F NAn 0573 0100 00031 00031 1000 5000 0010 1000 0175 00096 00096 1000 2865 0017 1146 0200 00126 00126 1000 2500 0020 1719 0300 00283 00283 1000 1667 0030 2000 0349 00383 00383 1000 1433 0035 2292 0400 00503 00502 1000 1250 0040 2865 0500 00785 00785 1001 1000 0050 3000 0524 00861 00861 1001 9554 0052 4000 0698 0153 0153 1001 7168 0070 5000 0873 0239 0239 1002 5737 0087 5730 1000 0314 0313 1003 5008 0100 1000 1745 0955 0947 1008 2880 0174 1146 2000 1252 1240 1010 2517 0199 1500 2618 2141 2104 1017 1932 0259 1719 3000 2806 2744 1023 1692 0296 2000 3491 3789 3675 1031 1462 0342 2292 4000 4960 4764 1041 1284 0389 2500 4363 5887 5611 1049 1183 0423 2865 5000 7692 7221 1065 1043 0479 3000 5236 8418 7854 1072 1000 0500 3438 6000 1097 1002 1096 0886 0565 4011 7000 1478 1304 1133 0776 0644 4500 7854 1840 1571 1172 0707 0707 4584 8000 1906 1617 1179 0697 0717 5157 9000 2377 1928 1233 0638 0783 5730 1000 2888 2224 1298 0594 0841 6000 1047 3142 2356 1333 0577 0866 7163 1250 4269 2830 1521 0527 0949 8595 1500 5839 3126 1868 0501 0997 9000 1571 6283 3142 2000 0500 1000 To obtain the numerical aperture NA numbers in this column must be multiplied by the index of refraction n of the local media Adapted from Nicodemus FE etal SelfStudV Manual on Optical Radiation Measurements NBS Technical Note 91001 National Institute of Standards and Technology Washington DC 1976 Effective technical communication demands a system of symbols units and nomenclature SUN that is reasonably consistent and that has widespread Such a system is the International System of Units SI There is no area where words are more important than radiometry and photometry document is an attempt to provide necessary and correct information to become acceptance APPENDIX V Radiometry vs photometry FAQ by James M Palmer Research Professor Optical Sciences Center University of Arizona Tucson AZ 85721 When I use a word it meansjust what Ichoose it to mean neither more nor less Lewis Carroll Charles Lutwidge Dodgson conversant What is the motivation for this FAQ What is radiometry What is photometry How do they differ What is projected area What is solid angle What are the quantities and units used in radiometry 1 2 3 4 5 6 7 8 9 How do 1 account for spectral quantities What are the quantities and units used in photometry What is the difference between lambertian and isotropic When do the properties of the eye get involved How do I convert between radiometric and photometric units 10 Where can I learn more about this stuff 1 What is the motivation for this FAQ There is so much misinformation and conceptual confusion regarding photometry and radiometry particularly on the WWW by a host of authorities it is high time someone got it straight So here it is with links to the responsible agencies Background It all started over a century ago An organization called the General Conference on Weights and Measures CGPM was formed by a diplomatic treaty called the Metre Convention This treaty was signed in 1875 in Paris by representatives from 17 nations including the USA There are now 48 member nations Also formed were the International Committee for Weights and Measures CIPM and the International Bureau of Weights and Measures BIPM The CIPM along with a number of subcommittees suggests modifications to the CGPM In our arena the subcommittee is the CCPR Consultative Committee on Photometry and Radiometry The BIPM is the physical facility responsible for dissemination of standards the international metrology institute The SI was adopted by the CGPM in 1960 It currently consists of seven base units and a larger number of derived units The base units are a choice of seven well defined units that by convention are regarded as independent The seven are metre kilogram second ampere kelvin mole and candela The derived units are those formed by various combinations of the base units International organizations involved in the promulgation of SUN include the International Commission on Illumination CIE the International Union of Pure and Applied Physics IUPAP and the International Standards Organization ISO In the USA the American National Standards Institute ANSI is the primary documentary protocol standards organization Many other scientific and technical organizations publish recommendations concerning the use of SUN for their learned publications Examples are the International Astronomical Union IAU and the American Institute of Physics AIP Read all about the SI its history and application at physicsnistgovcuu or at wwwbipmfr This FAQ was in essence the first draft modified to actually look like a FAQ of Chapter 7 Radiometrv and Photometrv Units and Conversions in the Handbook of Optics III McGrawHill 2001 2 What is radiometry What is photometry How do they differ Radiometry is the measurement of optical radiation which is electromagnetic radiation within the frequency range between 3gtlt1011 and 3gtlt1016 HZ This range corresponds to wavelengths between 001 and 1000 micrometres um and includes the regions commonly called the ultraviolet the Visible and the infrared Two out of many typical units encountered are wattsm2 and photonssecsteradian Photometry is the measurement of light which is defined as electromagnetic radiation detectable by the human eye It is thus restricted to the wavelength range from about 360 to 830 nanometers nm 1000 nm 2 1 pm Photometry is just like radiometry except that everything is weighted by the spectral response of the eye Visual photometry uses the eye as a comparison detector while physical photometry uses either optical radiation detectors constructed to mimic the spectral response of the eye or spectroradiometry coupled with appropriate calculations to do the eye response weighting Typical photometric units include lumens lux candelas and a host of other bizarre ones The only real difference between radiometry and photometry is that radiometry includes the entire optical radiation spectrum while photometry is limited to the visible spectrum as defined by the response of the eye In my forty years of experience photometry is more difficult to understand primarily because of the arcane terminology but is fairly easy to do because of the limited wavelength range Radiometry on the other hand is conceptually somewhat simpler but is far more difficult to actually do 3 What is projected area What is solid angle Projected area is defined as the rectilinear projection of a surface of any shape onto a plane normal to the unit vector The differential form is dApmj cos dA where l is the angle between the local surface normal and the line of sight We can integrate over the perceptible surface area to get A Icos dA pm A Some common examples are shown in the table below SHAPE AREA PROJECTED AREA Flat rectangle A LgtltW AproJZ LXW cos 5 Circular disc A 11 r2 11 d2 4 Aproj 11 r2 cos 5 11 d2 cos 5 4 Sphere A 4 11 r2 11 d2 Aproj A4 11 r2 Plane angle and solid angle are two derived units on the SI system The following definitions are from NlST SP811 The radian is the plane angle between two radii ofa circle that cuts off on the circumference an arc equal in length to the radius The abbreviation for the radian is rad Since there are 211 radians in a circle the conversion between degrees and radians is 1 rad 18011 degrees A solid angle extends the concept to three dimensions One steradian sr is the solid angle that having its vertex in the center of a sphere cuts off an area on the surface of the sphere equal to that ofa square with sides of length equal to the radius of the sphere The solid angle is thus ratio of the spherical area to the square of the radius The spherical area is a projection of the object of interest onto a unit sphere and the solid angle is the surface area of that projection If we divide the surface area of a sphere by the square of its radius we find that there are 411 steradians of solid angle in a sphere One hemisphere has 211 steradians The symbol for solid angle is either 0 the lowercase Greek letter omega or Q the uppercase omega 1 use 03 exclusively for solid angle reserving Q for the advanced concept of projected solid angle 03 cosG Both plane angles and solid angles are dimensionless quantities and they can lead to confusion when attempting dimensional analysis A12 4 What are the quantities and units used in radiometry Radiometric units can be divided into two conceptual areas those having to do with power or energy and those that are geometric in nature The first two are Energy is an SI derived unit measured in joules J The recommended symbol for energy is Q Power aka radiant flux is another SI derived unit It is the derivative of energy with respect to time dQdt and the unit is the watt W The recommended symbol for power is D the uppercase Greek letter theta An acceptable alternate is P Energy is the integral over time of power and is used for integrating detectors and pulsed sources Power is used for nonintegrating detectors and continuous sources Even though we patronize the power utility what we are actually buying is energy in watthours Now we become more specific and incorporate power with the geometric quantities area and solid angle Irradiance aka flux density is another SI derived unit and is measured in Wmz Irradiance is power per unit area incident from all directions in a hemisphere onto a surface that coincides with the base of that hemisphere A similar quantity is radiant eXitance which is power per unit area leaving a surface into a hemisphere whose base is that surface The symbol for irradiance is E and the symbol for radiant eXitance is M Irradiance or radiant eXitance is the derivative of power with respect to area dd7dA The integral of irradiance or radiant eXitance over area is power Radiant intensity is another SI derived unit and is measured in Wsr Intensity is power per unit solid angle The symbol is I Intensity is the derivative of power with respect to solid angle dQdoa The integral of radiant intensity over solid angle is power Radiance is the last SI derived unit we need and is measured in Wmzsr Radiance is power per unit projected area per unit solid angle The symbol is L Radiance is the derivative of power with respect to solid angle and projected area dQdoa dA cos0 where 0 is the angle between the surface normal and the specified direction The integral of radiance over area and solid angle is power A great deal of confusion concerns the use and misuse of the term intensity Some folks use it for Wsr some use it for VVm2 and others use it for Wmzsr It is quite clearly defined in the SI system in the definition of the base unit of luminous intensity the candela Some attempt to justify alternate uses by adding adjectives like optical used for Wmz or specific used for Wmzsr but this practice only adds to the confusion The underlying concept is quantity per unit solid angle For an extended discussion I wrote a paper entitled Getting Intense on Intensity for Metrologia official journal of the BIPM and a letter to OSA39s Optics and Photonics News with a modified version available on the web Photon quantities are also common They are related to the radiometric quantities by the relationship Q hcX where Q is the energy of a photon at wavelength 7 h is Planck39s constant and c is the velocity of light At a wavelength of 1 pm there are approximately 5x1018 photons per second in a watt Conversely also at 1 pm 1 photon has an energy of 2gtlt10 19 joules wattsec Common units include sec1m 2sr 1 for photon radiance 5 How do I represent spectral quantities Most sources of optical radiation are spectrally dependent and just radiance intensity etc give no information about the distribution of these quantities over wavelength Spectral quantities like spectral radiance spectral power etc are defined as the quotient of the quantity in an infinitesimal range of wavelength divided by that wavelength range In other words spectral quantities are derivative quantities per unit wavelength and have an additional 7V1 in their units When integrated over wavelength they yield the total quantity These spectral quantities are denoted by using a subscript 7t eg L9 EA 4 and I Some other quantities examples include spectral transmittance spectral re ectance spectral responsivity etc vary with wavelength but are not used as derivative quantities These quantities should not be integrated over wavelength they are only weighting functions to be included with the above derivative quantities To distinguish them from the derivative quantities they are denoted by a parenthetical wavelength ie SR0 or 50 6 What are the quantities and units used in photometry They are basically the same as the radiometric units except that they are weighted for the spectral response of the human eye and have funny names A few additional units have been introduced to deal with the amount of light reflected from diffuse matte surfaces The symbols used are identical to those radiometric units except that a subscript v is added to denote visual The following chart compares them QUANTITY RADIOMETRIC PHOTOMETRIC power watt W lumen lm power per unit area VVm2 lmm2 lux lx power per unit solid angle Wsr lmsr candela cd power per unit area per unit solid angle Wmzsr lmm2sr cdm2 2 nit Now we can get more specific about the details Candela unit of luminous intensity The candela is one of the seven base units of the S1 system It is defined as follows The candela is the luminous intensity in a given direction ofa source that emits monochromatic radiation offrequency 540x10 hertz and that has a radiant intensity in that direction of 163983 watt per steradian The candela is abbreviated as cd and its symbol is Iv The above definition was adopted by the 16th CGPM in 1979 The candela was formerly defined as the luminous intensity in the perpendicular direction of a surface of 1600 000 square metre of a black body at the temperature of freezing platinum under a pressure of 101 325 newtons per square metre This earlier definition was initially adopted in 1946 and later modified by the 13th CGPM 1967 It was abrogated in 1979 and replaced by the current definition The current definition was adopted because of several reasons First the freezing point of platinum 204219 was tied to another base unit the kelvin 1f the best estimate of this point were changed it would then impact the candela The uncertainty of the thermodynamic temperature of this fixed point created an unacceptable uncertainty in the value of the candela Second the realization of the Pt blackbody was extraordinarily difficult only a few were ever built Third if the temperature were slightly off possibly because of temperature gradients or contamination the freezing point might change or the temperature of the cavity might differ The sensitivity of the candela to a slight change in temperature is significant At a wavelength 555 nm a change in temperature of only 1K results in a luminance change approaching 1 Fourth the relative spectral radiance of blackbody radiation changes drastically some three orders of magnitude over the visible range Finally recent advances in radiometry offered new possibilities for the realization of the candela The value 683 lmW was selected based upon the best measurements with eXisting platinum freezing point blackbodies It has varied over time from 620 no nearly 700 lmW depending largely upon the assigned value of the freezing point of platinum The value of 1600 000 square metre was chosen to maintain consistency with prior standards Note that neither the old nor the new definition say anything about the spectral response of the human eye There are additional definitions that include the characteristics of the eye but the base unit candela and those SI units derived from it are eyeless Also note that in the definition there is no specification for the spatial distribution of intensity Luminous intensity while often associated with an isotropic point source is a valid specification for characterizing highly directional light sources such as spotlights and LEDs A15 One other issue before we press on Since the candela is now defined in terms of other S1 derived quantities there is really no need to retain it as an S1 base quantity It remains so for reasons of history and continuity Lumen unit of luminous flux The lumen is an S1 derived unit for luminous flux The abbreviation is lm and the symbol is Do The lumen is derived from the candela and is the luminous flux emitted into unit solid angle 1 sr by an isotropic point source having a luminous intensity of 1 candela The lumen is the product of luminous intensity and solid angle cdsr It is analogous to the unit of radiant flux watt differing only in the eye response weighting If a light source is isotropic the relationship between lumens and candelas is 1 cd 2 411 lm In other words an isotropic source having a luminous intensity of 1 candela emits 411 lumens into space which just happens to be 411 steradians We can also state that 1 cd 2 1 lmsr analogous to the equivalent radiometric definition If a source is not isotropic the relationship between candelas and lumens is empirical A fundamental method used to determine the total flux lumens is to measure the luminous intensity candelas in many directions using a goniophotometer and then numerically integrate over the entire sphere Later on we can use this calibrated lamp as a reference in an integrating sphere for routine measurements of luminous flux Lumens are what we get from the hardware store when we purchase a light bulb We want a high number of lumens with a minimum of power consumption and a reasonable lifetime Projection devices are also characterized by lumens to indicate how much luminous flux they can deliver to a screen Lux unit of luminous flux density or illuminance Illuminance is another S1 derived unit that denotes luminous flux density It has a special name lux and is lumens per square metre or lmm2 The symbol is El Most light meters measure this quantity as it is of great importance in illuminating engineering The IESNA Lighting Handbook has some sixteen pages of recommended illuminances for various activities and locales ranging from morgues to museums Typical values range from 100 000 lX for direct sunlight to 2050 lX for hospital corridors at night Nit unit of luminance Luminance should probably be included on the official list of derived SI units but is not It is analogous to radiance differentiating the lumen with respect to both area and direction It also has a special name nit and is cdm2 or lmm2sr if you prefer The symbol is Lu It is most often used to characterize the brightness of flat emitting or reflecting surfaces A typical use would be the luminance of your laptop computer screen They have between 100 and 250 nits and the sunlight readable ones have more than 1000 nits Typical CRT monitors have between 50 and 125 nits Other photometric units We have other photometric units boy do we have some strange ones Photometric quantities should be reported in SI units as given above However the literature is filled with now obsolete terminology and we must be able to interpret it So here are a few terms that have been used in the past Illuminance 1 metrecandle 1 luX 1 phot 1 lmcm2 104 luX 1 footcandle 1 lumenft2 1076 luX 1 milliphot 10 luX Luminance Here we have two classes of units The first is conventional easily related to the SI unit the cdm2 nit 1 stilb 1 cdcm2 104 cdm2 2 104 nit 1 cdft2 1076 cdm2 2 1076 nit The second class was designed to simplify characterization of light re ected from diffuse surfaces by including in the definitions the concept of a perfect diffuse re ector lambertian re ectance p 1 If one unit of illuminance falls upon this hypothetical re ector then 1 unit of luminance is re ected The perfect diffuse re ector emits 111 units of luminance per unit illuminance 1f the re ectance is p then the luminance is p times the illuminance Consequently these units all have a factor of 111 built in 1 lambert 11t cdcm2 1041t cdm2 1 apostilb 11t cdm2 1 footlambert 11t cdft2 3426 cdm2 1 millilambert 1011 cdm2 1 skot 1 milliblondel 1039311 cdm2 Photometric quantities are already the result of an integration over wavelength It therefore makes no sense to speak of spectral luminance or the like 7 What is the difference between lambertian and isotropic Both terms mean the same in all directions and are unfortunately sometimes used interchangeably Isotropic implies a spherical source that radiates the same in all directions ie the intensity Wsr is the same in all directions We often hear about an isotropic point source There can be no such thing because the energy density would have to be infinite But a small uniform sphere comes very close The best example is a globular tungsten lamp with a milky white diffuse envelope as used in dressing A17 room lighting From our vantage point a distant star can be considered an isotropic point source Lambertian refers to a at radiating surface It can be an active surface or a passive reflective surface Here the intensity falls off as the cosine of the observation angle with respect to the surface normal Lambert39s law The radiance W m2sr is independent of direction A good example is a surface painted with a good matte or flat white paint If it is uniformly illuminated like from the sun it appears equally bright from whatever direction you view it Note that the flat radiating surface can be an elemental area of a curved surface The ratio of the radiant eXitance W m2 to the radiance W m2sr of a lambertian surface is a factor of 11 and not 211 We integrate radiance over a hemisphere and find that the presence of the factor of cos9 in the definition of radiance gives us this interesting result It is not intuitive as we know that there are 211 steradians in a hemisphere A lambertian sphere illuminated by a distant point source will display a radiance which is maximum at the surface where the local normal coincides with the incoming beam The radiance will fall off with a cosine dependence to zero at the terminator 1f the intensity integrated radiance over area is unity when viewing from the source then the intensity when viewing from the side is 111 Think about this and consider whether or not our Moon is lambertian I39ll have more to say about this at a later date in another place 8 Where do the properties of the eye get involved We know that the eye does not see all wavelengths equally The eye has two general classes of photosensors cones and rods Cones The cones are responsible for lightadapted vision they respond to color and have high resolution in the central foveal region The lightadapted relative spectral response of the eye is called the spectral luminous efficiency function for photopic vision VL This empirical curve first adopted by the International Commission on Illumination CIE in 1924 has a peak of unity at 555 nm and decreases to levels below 10 5 at about 370 and 785 nm The 50 points are near 510 nm and 610 nm indicating that the curve is slightly skewed The VL curve looks very much like a Gaussian function in fact a Gaussian curve can easily be fit and is a good representation under some circumstances 1 used a nonlinear regression technique to obtain the following equation Vx1 1019e 285 MW More recent measurements have shown that the 1924 curve may not best represent typical human vision It appears to underestimate the response at wavelengths shorter than 460 nm Judd 1951 Vos 1978 and Stockman and Sharpe 1999 have made incremental advances in our knowledge of the photopic response Rods The rods are responsible for darkadapted vision with no color information and poor resolution when compared to the foveal cones The darkadapted relative spectral response of the eye is called the spectral luminous efficiency function for scotopic vision V Ot This is another empirical curve adopted by the CIE in 1951 It is defined between 380 nm and 780 nm The V Ot curve has a peak of unity at 507 nm and decreases to levels below 10 3 at about 380 and 645 nm The 50 points are near 455 nm and 550 nm This scotopic curve can also be fit with a Gaussian although the fit is not quite as good as the photopic curve My best fit is V11 E 09928421 9170 503Z Photopic light adapted cone vision is active for luminances greater than 3 cdm2 Scotopic darkadapted rod vision is active for luminances lower than 001 cdm2 In between both rods and cones contribute in varying amounts and in this range the vision is called mesopic There are currently efforts under way to characterize the composite spectral response in the mesopic range for vision research at intermediate luminance levels 1 EPHOTOPIC 08 06 04 02 SPECTRAL LUM INOUS EFFICIENCY 0 350 400 450 500 550 600 650 700 750 WAVELENGTH nm The Color Vision Lab at UCSD has an impressive collection of the data files including VL and V Ot that you need to do this kind of work A19 9 How do I convert between radiometric and photometric units We know from the definition of the candela that there are 683 lumens per watt at a frequency of 540THZ which is 555 nm in vacuum or air This is the wavelength that corresponds to the maximum spectral responsivity of the human eye The conversion from watts to lumens at any other wavelength involves the product of the power watts and the VL value at the wavelength of interest As an example we can compare laser pointers at 670 nm and 635 nm At 670 nm V4 is 0032 and a 5 mW laser has 0005Wgtlt0032gtlt6831mW 011 lumens At 635 nm VL is 0217 and a 5 mW laser has 0005Wgtlt0217gtlt6831mW 074 lumens The shorter wavelength 635 nm laser pointer Will create a spot that is almost 7 times as bright as the longer wavelength 670 nm laser assuming the same beam diameter In order to convert a source with nonmonochromatic spectral distribution to a luminous quantity the situation is decidedly more complex We must know the spectral nature of the source because it is used in an equation of the form XV ijowXV1d1 Where XV is a luminous term X is the corresponding spectral radiant term and VL is the photopic spectral luminous efficiency function For X we can pair luminous flux lm and spectral power W nm luminous intensity cd and spectral radiant intensity W srnm illuminance lx and spectral irradiance W m2nm or luminance cdmz and spectral radiance Wmzsrnm This equation represents a weighting wavelength by wavelength of the radiant spectral term by the visual response at that wavelength The constant Km is a scaling factor the maximum spectral luminous efficiency for photopic vision 683 lmW The wavelength limits can be set to restrict the integration to only those wavelengths Where the product of the spectral term X and VL is nonzero Practically this means we only need integrate from 360 to 830 nm limits specified by the CIE VL table Since this VL function is defined by a table of empirical values it is best to do the integration numerically Use of the Gaussian equation given above is only an approximation 1 compared the Gaussian equation with the tabulated data using blackbody curves and found the differences to be less than 1 for temperatures between 1500K and 20000K This result is acceptable for smooth curves but don t try it for narrow wavelength sources like LEDs There is nothing in the SI definitions of the base or derived units concerning the eye response so we have some exibility in the choice of the weighting function We can use a different spectral luminous efficacy curve perhaps one of the newer ones We can also make use of the equivalent curve for scotopic darkadapted vision for studies at lower light levels This V39O curve has its own constant K39m the maximum spectral luminous efficiency for scotopic vision K39m is 1700 lmW at the peak wavelength for scotopic vision 507 nm and this value was deliberately chosen such that the absolute value of the scotopic curve at 555 nm coincides with the A20 photopic curve at the value 683 lmW Some workers are referring to scotopic lumens a term which should be discouraged because of the potential for misunderstanding In the future we can also expect to see spectral weighting to represent the mesopic region The International Commission on Weights and Measures CGPM has approved the use of the CIE V4 and V0 curves for determination of the value of photometric quantities of luminous sources Now about converting from lumens to watts The conversion from watts to lumens that we saw just above required that the spectral function X of the radiation be known over the spectral range from 360 to 830 nm where VL is nonzero Attempts to go in the other direction from lumens to watts are far more difficult Since we are trying to back out a quantity that was weighted and placed inside of an integral we must know the spectral function X of the radiation over the entire spectral range where the source emits not just the visible There are a few tricks which appear in Chapter 7 Radiometry and Photometry Units and Conversions in the Handbook of Optics III McGrawHill 2001 10 Where can I learn more about this stuff Books significant journal articles DeCusatis C Handbook of Applied Photometry AIP Press 1997 Authoritative with pertinent chapters written by technical eXperts at BIPM CIE and NIST Skip chapter 4 Rea M ed Lighting Handbook Reference and Application 8th edition Illuminating Engineering Society of North America 1993 Symbols Units and Nomenclature in Physics International Union of Pure and Applied Physics 1987 American National Standard Nomenclature and Definitions for Illuminating Engineering ANSI Standard ANSIIESNA RP16 96 The Basis of Physical Photometry CIE Technical Report 182 1983 Publications available on the World Wide Web All you ever wanted to know about the SI is contained at BIPM and at NIST Available publications highly recommended include The International System of Units SI 7th edition 1998 direct from BIPM The official document is in French this is the English translation Available in PDF format NIST Special Publication SP330 The International System of Units SI The US edition of the above BIPM publication Available in PDF format NIST Special Publication SP811 Guide for the Use of the International System of Units SI available in PDF format Papers published in recent issues of the NIST Journal of Research are also available on the web in PDF format Useful Web sites BIPM International Bureau of Weights and Measures WWWbipmfr NIST National Institute of Standards and Technology physicsnistgovcuu ISO International Standards Organization WWWisoch ANSI American National Standards Institute WWWansiorg CIE International Commission on Illumination WWWciecoatcie IESNA Illuminating Engineering Society of North America WWWiesnaorg IUPAP International Union of Pure and Applied Physics WWWphysicsumanitobacaiupap Color Vision Lab at UCSD cvisionuscdedu AIP American Institute of Physics WWWaiporg SPIE International Society for Optical Engineering WWWspieorg OSA Optical Society of America WWWosaorg CORM Council of Optical Radiation Measurements WWWcormorg Version 101 08 June 1999 Send corrections and comments to the author email jmpalmeruarizonaedu or jpalmerazstarnetcom WW W WWWopticsarizonaeduPalmer lf Noise An product Bandwidth nonnallzauon Blackbody radianon simulawr BLIP Bode plot ERDF Brightness temperature KrDF Charge transfer ef ciency Chopping factor APPENDIX VI Weucl uhlqultcus nclse fmm many familial and stxange scuzces lnvexsely pmpumunal ta fxequenny plnh cl Ed nclse An appmxlmatmn ls T 7 canst 123 I1 39 GLOSSARY whale u ls between 1 25 and 4 typlcally 2 and a ls between 0 a and a typlcally 1 Alsc callecl lckex ccntact excess mcdulatlcn an A map palnl symhal T unlts mzrsx geametucal tenn zelatlng ta amauntafpcwez thatcan get Lhmugh a system a k a thxaughput etenclue Detennlnatlcn nf an equualent xespnnslvlty uslnga xentangle the 31235 undez the cuxve and lectangle axe set equal An abject that sunulates hlachhccly Flancluan Iadlahnn Vla cazeful navlty cleslgn ancl Lempexatuxe measuxement BankgmunerlmnEd lnhazeclPhctccletectcz cne whcse nDlsE ls pledumlnandy clue la the nDlsE ln the lncldent phDLDn stzeam nut lnLunsln LU the detenmx Flumng lugslgnal cl nclse vs lugfzequ2ncy r shcws many Dzdezs cfmagnltucle asymptctes ufllneaz plats map ta stzalghtllnes an Eccle plat Bldlxenuunal Re ectance Dlstnhutlcn Functlcn A duectlcnal uuantlty that denctes cutput IadlanCE as a functlcn cfcluectlcn and lnacllance A pexfec y dlffuslng leflectcl has aERDF ufpn whlle a pexfectly speculaz xe ecmz has a ERDF pm p15 leflectance and s ls the FSA cf the sauna Unlts sr Thehnghtness Lempexatuxe ufan abject ls the Lempexatuxe nfblackhndy Iadlahnn that has the same spectxal zadlanne as the abject Bldlxenuunal Tzansmlssmn Dlstnhutlcn Functan The angulax chstnhutlcn uftzansmltted zadlanne amund the nnxmal Llansmlttedbeam Unlts 51quot anCLan chhaxge that ls successfully Llansfeued fmm cne CCD chaxge smxage element patentlal well ta the adjacent nhaxge stcxage element Ratlc cf the xms amplltude cf the fundamental CIE chromaticity diagram Cold filter Cold stop Collimator Color temperature Conduction calorimeter Contrast sensitivity function Correlated color temperature Cosine response D D more here DBLIP frequency component of a modulated signal to the peaktopeak amplitude of the unmodulated signal Equal to 7I2 045 for square wave chopping A horseshoe shaped diagram showing the gamut of all possible colors in terms of hue and saturation The horseshoe is the spectrum locus and white is at the center where X y z 13 A filter that passes desired bandpass and is cooled to minimize selfradiation at other wavelengths An aperture placed in front of a detector to limit the field of View and cooled to minimize the stop radiance Improves SNR An optical system designed to make a near small source appear as if it were located at infinity The color temperature of an object is the temperature of blackbody radiation that has the same chromaticity color as the object A device to measure laser power and energy by calorimetric means ie heating of an absorber The visual acuity of the eye as a function of both spatial frequency and contrast Determined by looking at variable frequency cos2 wave patterns that have contrast decreasing from bottom to top The temperature of a blackbody having a chromaticity colour as close as possible to the chromaticity of the source in question The response curve desired for an instrument designed to measure irradiance from a hemisphere Related to projected area Detectivity the reciprocal of NEP It is the SNR per watt for a 1 detector Unit W 1 Specific or normalized detectivity It is detectivity D NEP 1 normalized for bandwidth and area DAB1 2NEP Unit cmHzl Zer It is the SNR per watt for a 1 cm2 detector with a bandwidth of 1 Hz Allows a fair comparison between detector types A normalized detectivity taking into account detector area noise bandwidth and FOV It s the SNR per incident watt for a 1 cm2 area 1 Hz noise bandwidth and n sr of projected solid angle DABQ1I1 2NEP Unit cmHzl ZW 1 a further normalization for field of view DQn 2 Backgroundlimited infrared photodetector the best SNR you can get when photon noise from the Decade octave Decibel Detective quantum efficiency DQE Diffuse re ectance Distribution temperature Effective noise bandwidth Electrical substitution radiometer Full well capacity Generationrecombination noise HD curve Hemispherical reflectance Iluminance background limits Frequency ratio of 10 and 2 respectively dB a ratio of two voltages currents or powers V I P 613 2010g10 72 2010g10 1 2 dB 1010g10 F2 1 1 1 It is a relative measure There are several ways of denoting absolute values dBv dBm referred to 1 volt rms referred to 1 mW with stated impedance 759 6009 To compare unlike waveforms such as a sine wave to gaussian noise use the power formulation A relative measure of the amount of noise added by a detector Detective quantum efficiency like RQE but includes noise SNRout2SNRin2 unitless 0ltDQElt1 Ratio of radiation re ected into a hemisphere whose base is the re ector to the incident radiation Excludes specular component The distribution temperature of an object is the temperature of a blackbody radiator that has the same or nearly the same relative spectral distribution over a substantial portion of the spectrum as the object The equivalent squareband power bandwidth used for evaluation of noise Given for quotwhitequot noise by 1 w 2 A 10 Af df o The equivalent brickwall rectangular passband Alternate symbols are E and Af units are Hz ENB A radiometer based upon a thermal detector with provisions for injecting a known power via electrical means for the purpose of calibration The number of electrons signal noise dark current that a potential well in a CCD structure can hold Noise due to the generation of carriers by photon absorption and by recombination random motion of carriers electrons in a resistive material Spectral power density depends on frequency The characteristic curve of photographic film named after Hurter and Driffield which plots density log1t vs log of the exposure product of irradiance and time Directional emittance integrated over an entire hemisphere Luminous ux per unit incident on a surface from a Intensity Irradiance Isotropic point source Johnson noise Jones calibration con guration Lambertian source Laser calorimeter Luminance Luminous intensity Measurement equation Moments normalization Noise Equivalent Photon Flux Noise Equivalent Power hemisphere units lmm2 luX Analagous to irradiance in Wmz Symbol I watts per unit solid angle often from an isotropic quotpointquot source Wsr391 symbol E units Wm39z watts per unit area incident on a surface Small relative to distance source where intensity is independent of direction Noise due to random thermal agitation of carriers electrons in a resistive material Spectral power density independent of frequency ie white v 4kTRB or 139 4kTB R Also known as near small source The radiometer is focussed at infinity A small calibration source is placed within a cone whose base is the entrance aperture and whose halfangle is the chief ray angle It fills a fraction of the entrance aperture The calibration equation is 5R A LA Source where radiance is independent of direction A device to measure laser energy particularly for short pulses by calorimetric means ie heating of an absorber Output proportional to time integral of power ie energy Photometric equivalent of radiance Measure of visible power per unitprojected area per unit solid angle Unit candelam2 lumenmzlsr Measure of visible power per unit solid angle Unit candela cd lumensr One of the seven Sl base units Analogous to radiant intensity Wsr An equation that relates the output signal from a detector or radiometer to a function of the receiver and source spectral parameters An example SIG AQIOwLSR1d1 A normalization based on a moments analysis of a spectral responsivity The center wavelength is the centroid and the bandwidth and cuton and cutoff wavelengths are computed from the variance The photon phluX incident on a detector which gives rise to a signaltonoise ratio of one Units sec 1 The power incident on a detector which gives rise to a NEP Noise Equivalent Temperature Difference NETD NEAT Passband normalization Peak normalization Photoconductive gain Photon noise Photopic Photopic Visibility curve Precision Projected solid angle Quantum efficiency Quantum trap detector Radiance Radiance temperature Radiant eXitance Radiant intensity Radiation reference signaltonoise ratio of one Units watt The temperature difference between the target and the background that produces an rms signal equal to the rms noise Normalization method wherein the band limits of the equivalent rectangle are assigned at fixed response points 50 10 1e etc The normalized responsivity is then related to the area under the response curve A normalization where the band responsivity is set to the peak of the actual response curve The bandwidth is calculated by matching the area of the equivalent rectangle to the area under the response curve The ratio of the transit time to the carrier lifetime for a photoconductive detector A measure of the number of electrons a single absorbed photon can generate Noise due to the random arrival of photons manifest as shot noise or the g component of gr noise Pertaining to lightadapted vision The relative spectral responsivity of the standardized lightadapted human eye cones Symbol is V0 dimensionless A measure of the repeatability of a measurement Comes from granularity noise etc Determined and enhanced by repeated measurements Solid angle x cos 6 projected onto at surface dQdm cose Symbol 2 units sr see Responsive Quantum Efficiency A multiple detector array where detectors are placed in series optically and in parallel electrically Has a quantum efficiency approaching unity Fundamental unit of radiometer directional Symbol L units Wm Zsr 1 The radiance aka brightness temperature of an unknown object is the temperature of a blackbody that has the same spectral radiance as the unknown object Radiant power per unit area leaving a source into a hemisphere Symbol M units Wm 2 Radiant power per unit solid angle Wsr391 A comparison source for a radiometer zerobased for shortwave radiometers a known thermal source for longwave radiometers Radiation temperature Range equation Ratio temperature Re ectance factor Responsive quantum efficiency RQE ResponsiVity Retrore ectance rms root mean square Saturation exposure Scotopic Visibility curve Shot noise The radiation temperature of an object is the temperature of blackbody radiation that has the same total integrated over all wavelengths radiance as the object An equation that gives the distance from a source that one can detect with a stated SNR The ratio temperature of an object is the temperature of blackbody radiation that has the same ratio of spectral radiances at two wavelengths as the object Ratio of ux re ected from a sample to the ux that would be re ected from a perfect diffuse re ector lambertian p 1 The number of independent output events per incident photon Dimensionless between 0 and 1 Symbols n RQE Ratio of the output of a detector to its input Units usually AW or VW Symbol is 9 The result of an integral over wavelength ISR1qgtd1 Mad1 Wherein the re ected beam retraces the path from the source back to the source A measure of the equivalent heating effect of a voltage or current 1 T 2 VW FL v tdt where T is time usually a single or integer multiple of periods for periodic waveforms For a sine wave the rms voltage is 1N2 times the peak voltage measured from 0 or 122 times the peaktopeak voltage Electric power companies deliver 117Vrms which is 330Vpp For a square wave the rms amplitude is the same as the peak amplitude The exposure product of irradiance and time necessary to saturate an integrating detector Used for CCD CID and CMOS array detectors Unit wattsmz The relative spectral responsivity of the standardized darkadapted human eye rods Peaks at 507 nm Dimensionless symbol is VlOL Noise associated with current ow across a potential barrier due to discreet nature of electrons Power spectral density is independent of frequency ie Solid angle Spectral directional emissivity Spectral radiance Spectral radiant intensity Spectral reflectance Spectral responsiVity Specular reflectance Throughput Time constant Total hemispherical emissivity Transimpedance amplifier Trap detector Type A error white Mean square shot noise current 139 ZquEB Projected area distance2 given by 2711cos 612 for right circular cone Symbol m units sr The ratio of radiance at a specified wavelength in a particular direction to that of a blackbody at the same wavelength and in the same direction Symbol Lb watts per unit area per unit projected solid angle per unit wavelength interval fundamental unit of radiometry Symbol 1 units Wsr lMm l watts per steradian per unit wavelength often from an isotropic quotpointquot source Ratio of re ected power at a specific wavelength to the incident power at the same wavelength Responsivity as a function of wavelength Symbol SRO Units amps or volts etc per watt Not a derivative quantity per unit wavelength interval Ratio of radiation re ected in the mirror direction to the incident radiation Excludes diffuse scattered component Symbol T units mZsr geometrical term relating to amount of power that can get through a system The product of area and projected solid angle A9 A measure of the speed of response of a device The time required to reach 11e or 0632 of the final value in response to a step input Symbol T units are sec For a simple RC circuit 39FRC Integral of spectral directional emissivity over the entire spectrum and over an entire hemisphere aka currenttovoltage converter used to interface with current sources i J A multiple detector array where detectors are placed in series optically and in parallel electrically Has a quantum efficiency approaching unity R N39 Older term Precision Aka random error A measure of the repeatability of a measurement Comes from granularity noise etc Determined by repeated Type B error Uncertainty Wien s displacement law Wien approximation measurements Older term Accuracy Aka systematic error or bias A measure of the difference between the mean reading and truth May b e corrected by careful calibratioon and characterization The total estimated difference between a measurement and truth includes both random and systematic error terms and a confidence parameter Product of wavelength and temperature a constant An equation representing blackbody radiation at short wavelengths andor low temperatures Form is C 7 AT Mfg gem 9 APPENDIX VII SUPPLEMENTARY NOTES 1 Effective noise bandwidth 2 Full derivation of moments bandwidth normalization 3 Jones NSS calibration configuration original derivation DRAFT COPY EFFECTIVE NOISE BANDWIDTH OF RC FILTERS AND THE SELECTION OF FILTER PARAMETERS TO OPTIMIZE SNR James M Palmer Optical Sciences Center University of Arizona Tucson AZ 85721 ABSTRACT 1 Introduction Engineering calculations involving noise and signaltonoise ratio need to use the effective noise bandwidth ENB in order to calculate noise properly Often the conventional 3dB voltage 6dB power bandwidth is used leading to erroneous results When the difference between 3dB bandwidth and ENB is recognized it is often oversimplified by attempting to relate ENB to the 3dB bandwidth Table 1 shows several of these relationships I found in the open and corporate literature Table 1 Ratio of ENB to SdB bandwidth for lowpass filters SECTIONS B C D E 157 157 157 122 111 112 115 105 108 113 1025 106 5 111 105 A CD Motchenbacher amp JA Connelly Low Noise Electronic System Design Wiley NY 1993 sec 14 B HW Ott Noise Reduction Techniques in Electronic Systems Wiley NY 1976 Table 82 C P Horowitz amp W Hill The Art of Electronics Cambridge NY 1989 sec 721 D Ithaco Measuring Noise Spectra with Variable Electronic Filters Ithaco Application Note IAN102 Ithaco Corp Ithaca NY 783 Appendix 1 EEL Dereniak amp GD Boreman Infrared Detectors and Systems Wiley NY 1996 Table 51 These discrepancies while not extremely serious are disconcerting particularly for the twosection filter which is readily realizable with a single operational amplifier and a handful of R and C components So I set off to find out which values are correct This was accomplished by means of simple spreadsheet analysis and BASIC computer programs to do the necessary integrations There are many multiplepole filter types in the literature This paper is limited to simple Butterworth RC filters where each section has the same R and C and therefore cutoff frequency The primary emphasis is limited to white noise with a uniform power spectral density We conclude with a simple bandwidth optimization to maximize the SNR of a singlefrequency signal in the presence of white noise 2 Definitions The signal bandwidth of a lowpass filter is defined as the frequency where the signal voltage falls to 3dB lb220707 of the transmission at DC typically unity This frequency is also referred to as the halfpower point where the power transmission has dropped to 6dB 05 For a bandpass filter the same terms are used relative to the peak transmission of the filter The bandwidth is often referred to as FWHM fullwidth at halfmaximum for power Figures 1 and 2 show these terms for a simple lowpass and bandpass filters respectively The signal bandwidth is not appropriate for characterization of noise The effective noise bandwidth ENB more often seen as B or Af is defined as the equivalent brickwall rectangular filter having the same area under the power transmission curve The equation is B 1 G EJ39Gfvfzdf 1 where G is the power gain as a function of frequency and f0 is the frequency where G is a maXimum vf2 is the power spectrum for the noise under consideration and 102 is the noise power at the peak frequency For quotwhitequot spectrally at noise equation 1 simplifies to l 3602 jam df lt2 and this format is most often seen In electrooptical systems this bandwidth may be limited by the frequency response of a detector or its associated electronics or by the insertion of an electrical filter operating in the audio to low radio frequency range 20 Hz to several Mhz Figures 1 and 2 also show the ENB white noise for lowpass and bandpass filters The signaltonoise ratio SNR SN of a system is the ratio of the rms signal current isig to the rms noise current in Voltage may be substituted for current SNR is dimensionless Use of rms is indicated as it is the only measure appropriate for the characterization of random noise 3 Lowpass filters The voltage transmission of a singlesection RC lowpass filter is 1 3 where a is the radian frequency equal to 2717 in HZ and r is the circuit time constant the RC product At low frequencies 0339 ltlt 1 A is unity The transmission curve drops to 3dB in amplitude at the point where 0 5 2 1 and falls at 6dBoctave 20 dBdecade at higher frequencies 0339 gtgt1 The cutoff frequency is defined as the 3dB 0707 point although there is substantial transmission for higher frequencies The 3dB point is at 11 radianssec or 12m HZ The ENB of this simple filter is readily found by integrating the square power transmission of equation 3 in closed form the result is TEZ E in radianssec or 141 112f0 expressed in HZ The ENB is therefore 112 or 1571 times the 3dB bandwidth and everybody in Table 1 agrees A For higher order filters the closedform integration becomes more complex so I chose numerical techniques by writing a simple BASIC program and using a spreadsheet It must be noted that whenever two or more RC sections are cascaded the 3dB point for the new composite filter shifts to lower frequencies one does not use the 3dB point for a single RC section In addition multiple sections are buffered isolated from each other so that subsequent sections present no loading to preceeding sections The results of the integrations are shown in Table 2 Table 2 Low pass filter characteristics matched sections w 3dB f 3dB ENB ENB RATIO SECTIONS radsec Hz radsec Hz ENBB3b 1 11 12111 1121 141 nZ 1571 2 06441 01021 Tit4 181 1220 3 05101 00811 05891 00941 1155 4 0435 5 0069 5 0492 5 0078 5 1130 5 0386 5 0061 5 0430 5 0068 5 1115 6 0350 5 0056 5 0387 5 0062 5 1106 These results confirm that the values given by Motchenbacher amp Connelly and by Ott in Table 1 are correct 4 Bandpass filters with matched time constants The simple RC bandpass filter with matched time constants adds a single hipass filter to a single lopass filter each with the same time constant 139 RC The voltage transmission of a singlesection RC hipass filter is A L 4 quot1a22r2 where a is the radian frequency equal to 2717 in HZ and r is the circuit time constant the RC product in seconds At high frequencies A approaches unity and the curve falls at 6dBoctave 20 dBdecade at lower frequencies The cutoff frequency is defined as the 3dB 0707 point even though there is substantial transmission at lower frequencies The 3dB point where 0322 1 is 1 c radianssec or 12m HZ The peak transmission for these simple bandpass filters is no longer unity and the 3dB bandwidth points must be evaluated with respect to the peak transmission of the composite filter not unity For the single section bandpass filter a peak transmission of 05 6dB is found located at the coincidence of the 3dB points of the hipass and lopass sections The 3dB passband of the bandpass filter is determined at 3dB below this level or at 9dB 03535 The closed form integration of this singlestage bandpass filter gives an ENB of nfc Results for filters with one to four sections are shown in Table 3 Table 3 Bandpass filter characteristics matched sections SECTIONS 1 2 3 4 Peak trans 05 025 0125 00625 B3dBfc 1Q 2 1287 1019 0871 fLPfc 0414 0546 0613 0655 fHPfc 2414 1833 1632 1526 ENBfc TE n2 1177 0982 fLPfc 0291 0486 0572 0623 fHPfc 3432 2057 1749 1605 ENBB3dB n2 1220 1155 1127 It should be noted that the cuton and cutoff frequencies are disposed about the center frequency in a geometric sense ie fL12gtltfH1nfc2 where fc is the center frequency of the filter The location of pr is given by fLPBZ4 B 5 where B is either the 3dB bandwidth or the ENB fH is then fezfL 5 Bandpass filters with different time constants Here we discuss bandpass filters constructed using a single hipass section in series with a single lopass section Each section has a different time constant Figures 3 and 4 shows a typical bandpass filter voltage and power transmissions with the bandwidths superimposed First we note that the minimum bandwidth is achieved with the lopass cutoff and hipass cuton frequencies matched If the lopass cutoff is chosen at a lower frequency than the hipass cuton frequency the resulting bandwidth remains the same as the case where the two frequencies are identical The only thing achieved is a reduction in filter transmission A simple BASIC program was written to find the ENB the peak transmission the 3dB points and the 3dB bandwidth for these filters Again the integrations were done for several selections of lopass cutoffs and hipass cuton frequencies and the 3dB points were located with respect to the composite transmission The results are shown in Table 4 for a singlesection bandpass filter These calculations were done holding pr constant at unity Table 4 ENE for bandpass filters where pr Z pr P P T eak B 3dB ENB 1 05 2 314 15 06 25 391 0667 470 075 626 08 782 0833 939 0857 1096 0909 1720 0952 3278 From these data we find some surprisingly simple relationships The maximum transmission is given by fun T pzak fLPfHP and if pr gtgt pr the peak transmission approaches unity as expected The 3dB bandwidth is given by 6 Badly fLP fHP 7 so that if pr gtgt pr the 3dB bandwidth approaches that of the lopass filter alone The effective noise bandwidth is given by 7139 ENE 337W 8 Figure 763 in Horowitz and Hill shows a simple equation to relate the ENB for this case to the individual cuton and cutoff frequencies 2 ENE 9 2 leP fHP If we were to use equation 9 to determine the ENB in the special case where pr pr it shows that the ENB is 114 times the 3dB bandwidth which is less than the 3dB bandwidth a surprising result This analysis shows that the ENB is 112 times the 3dB bandwidth It can be seen than when fL gtgt fH the results of equation 9 converge to the correct solution just that of the lowpass filter alone A comparison between these new calculations for ENB and the results predicted using equation 9 is given in Table 5 It is apparent that equation 9 gives erroneous results Table 5 Comparison with Horowitz and Hill ENB E nation 9 11 114 470 209 939 655 1720 1428 3278 299 6 Filter selection to optimize SNR We now address the selection of the optimum filter to maximize the signaltonoise ratio For many applications we can ignore preservation of the signal waveform to achieve better SNR We shall recover just the fundamental with maXimum SNR Our discussion will be limited to white noise uniform power spectral density For the lowpass filter the choice of cutoff frequency fC was determined using a short BASIC program to iterate fC for a fixed signal frequency of 100 arbitrary units The results are shown in Figures 5 and 6 for single and multiplesection lo pass filters respectively In the second case the frequencies are adjusted to place the 3dB point of the composite filters at the same frequency as the singlesection filter These results show that for the singlesection filter the best SNR is obtained when fC is equal to the signal fundamental frequency The results differ little for multisection lopass filters The doublesection filter achieves its peak SNR at a frequency slightly higher 111 times the composite 3dB point than for the singlesection filter If we choose the composite 3dB point the SNR is 0991 times the maXimum achievable SNR Three and foursection filters showed similar results the peak SNR was realized at about a 15 higher cutoff frequency but the SNR at the composite 3dB point was within 1 of the maXimum SNR Satisfactory results will be achieved by using the composite 3dB frequency for 1 to 4 section lopass filters For the simple bandpass filter where the hipass and lopass sections are set to the same frequency the optimum SNR is achieved by setting both 3dB points at the signal frequency as that will maximize signal transmission It was hypothesized that if the bandpass were increased somewhat the transmission at the peak may increase faster than the noise which is proportional to the square root of the ENB To test this hypothesis further spreadsheet work was done to implement the calculations 1 again chose to keep the geometric mean of the lopass and hipass sections equal to the center frequency ie fLP gtlt fHP fcz The results are shown in Figure 7 It can be seen that the optimum SNR is achieved when the passband is defined where fLfH It can also be seen that setting the lopass section to a lower frequency than the hipass section is futile yielding the same SNR with both signal and noise attenuated equally These above results are valid only for white noise Every practical circuit has at a minimum a single RC time constant associated with it defining an ENB and a corresponding SNR If additional noise filtering is necessary we can add a simple active filter using a single operational amplifier with two RC sections It is then interesting to consider the simple bandpass filter one section each matched hipass and lopass and one and twosection lowpass RC filters The bandpass filter has an ENB of 11 and a peak gain of 05 whereas a single section lowpass filter has an ENB of nZ and a gain of unity The noise transmission the product of the peak transmission and ENBlz is 1253 for the lo pass filter and 0886 for the bandpass filter The signal transmission for the lopass filter is 0707 whereas it is 05 for the bandpass filter The SNR for each is therefore the same However for a twosection lowpass filter with the signal at the composite 3dB frequency the ENB is 1220Xfc the noise transmission is 1105 the signal transmission is 0707 and the SNR is therefore improved by some 135 over the simple bandbass and singlesection filters 7 Conclusions Several recommendations can be made 1 A doublesection lopass filter is sufficiently better in the reduction of white noise to warrant the use of two additional components 2 1n the absence of 1f noise a twosection lopass filter will outperform a bandpass filter with the same number of components DRAFT COPY BANDWIDTH NORMALIZATION BY MOMENTS General measurement equation 1 0 51mm cm 1 If SRO can be represented as a rectangle 42 1 SRHL qgtd1 2 Let the source function d3 be described as a seconddegree polynomial QAABA C22 3 Substitute 3 into 1 diVide both sides by ISRltgtLgt d and multiply both sides by A2 7L1 to get 315R 1 cm 312 1 cm 122 21 ABlo Clo U Kama1 Kama1 Kama1 12 W11 4 Next integrate 3 between the limits 11 and 12 J d2A z21 2M2522 21 5 Note the similarities between Eqs 4 and 5 If the following conditions are applied 22 2 0 ASHUM i l f 2 IO AZSRUtdA 6 2 w 3 w 0 SR1d1 0 SR1d1 M I L dadl 521 7 lo Assume that area of response curve 2 area of equivalent rectangle ie SR M 0 mam 8 Then j q qa d1 i 9 1 a 5R lt gt and we have a band limited power din band Now we proceed to determine 11 12 and 5RD Substitute 315R 1 cm 312 1 cm A11 you A12 you 0 5R1d1 0 SR1d1 Then MF MZZW 11 M1 is the first moment divided by the area zeroth moment and is the centroid of the response curve the effective or center wavelength M2 is the second moment divided by the area which is related to the square of the radius of gyration Solution of simultaneous Eqs 11 with the substitution M1 xlc yields 21 25 43042 252 22 1 J3M2 1f 12 showing the bandpass limits 11 and 12 are symmetrically disposed about the center wavelength 1 The quantity M2 232 is recognized as the variance 03 The bandwidth between wavelength limits 11 and 12 is Aka 252 13 and the short and long limit wavelengths are then 1115 J3 039 zlcJ3 O39 14 The bandwidthnormalized responsivity is 1 no Now we have our three parameters 5RD 11 and 12 Note that the coefficients A B and C of the seconddegree source polynomial Eq 3 have vanished The implication is significant Anx source that can be represented by a seconddegree polynomial can be characterized between the wavelength limits X1 and X2 which are determined solely by the radiometer m w There is no ambiguity in any of the normalization parameters they are all uniquely determined from only the spectral responsivity curve The errors are related to the deviation of the source function from a quadratic MOMENTS NORMALIZATION SUMMARY This is the stepbystep procedure for accomplishing a moments normalization The starting point is absolute spectral responsivity ER7 Zeroth moment M 0 KENUM First moment M1 I AER ad1 Second moment M 2 I 12 SRtd1 M1 Center wavelength centr01d 1 V 0 2 M 2 2 1 Variance 0 M0 5 Short wavelength limit 11 x1 J50 Long wavelength limit 12 x1 50 Bandwidth M 2J a N 139 d 39 39t SR Mquot onna 1ze respons1v1 y n 2 50 JONES NSS CALIBRATION CONFIGURATION The following pages are a replica of an obscure application note further describing the near small source method of radiometric calibration A copy of the original document believed to be an application note from Block Engineering was scanned then modern terminology was added How to calibrate a radiometer A simple method of calibrating a radiometer using a small blackbody source close to the radiometer aperture has been described by Dr R Clark Jones of the Polaroid Corporation The principles involved in this method are briefly reviewed here with special emphasis on the application to the Optitherm Radiometer Cassegrain system The essential point in the method is that a small radiation source close to the aperture of the Radiometer will uniformly irradiate an area in the focal plane of the Radiometer The radiation on the detector with the radiometer focussed at infinity is then given by ORIGINAL EQUATION MODERN SYMBOLS WZBSASOJr qDZLSAswr 1 where W 2 radiation on detector watts B5 2 Source radiance wattssteradiancm2 Ls As 2 Source area cm2 car 2 Solid angle of radiometer field of view steradian 7 detector area focal length2 Thus the responsivity of a detector in a Radiometer can readily be calibrated by dividing the signal voltage output of the instrument by the radiation on the detector An important aspect of the method is that the radiation on the detector is independent of the Radiometer aperture and source location providing a uniformly irradiated area covers the detector This restriction places limits on the source size and location as given below For a point source see Fig 1 the diameter of the uniformly irradiated disc Df in tie focal plane is given by Df 1231 2 where f focal length of Radiometer P distance from vertex of optical system primary mirror to source DPl diameter of entrance pupil of radiometer usually diameter of primary mirror Dpi ENTRANCE PUPIL FOCAL 0F RADIOMETER Fig 1 If the Radiometer optical system is of the Cassegrain type an obscured area will result and the uniformly irradiated area will then be an annular ring of width Xand mean diameter DIn 1 f I EFltDP1 Dpz 3 Where Dpz Diameter of obscured disc produced by secondary mirror 1 Dm 25DP1DP2 4 If as is always the case the source has a finite diameter Ms see Fig 2 the edges of the disc or ring will be vignetted by an amount f MS P divided equally on either side of the unblurred edge The remaining uniformly irradiated disc or annular ring width is given by Dx 2DP1MS 23 l 12 DP1DP2MS 3a The mean diameter of the ring remains the same as given in 4 Dpi SOURCE M s szUNIFORMLY IRRADIATED DISC Fig 2 In calibrating a Radiometer a convenient source aperture and distance are first chosen Then the size of the uniformly irradiated area must be checked to see whether it covers the detector For example if a Cassegrain system is used the detector must fit in the ring of width 2 and mean diameter D as computed from equations 3a and 4 The source must be placed offaxis such that the annular ring of width X falls on the detector Several other precautions must be observed particularly if a thermal detector is used Since the calibration source fills only a small part of the field of view the detector will see other radiation as well If the source is chopped the Radiometer will respond only to it However in many cases the detector is chopped and hence it responds to all radiation in its field of view One way of separating the response to the calibration source from the background is to record the difference in response when the source aperture is opened and when it is closed APPENDIX VIII DOCUMENTARY STANDARDS FOR 9 RADIOMETRY AND PHOTOMETRY Numexous agencles pxepaxe and dassemmate documentaxy pzoLoCol standaxds fox xadnometzy and allled he1ds Those hsted hexe axe eJLhex US 01 nLeznahonal standazds ozgamzahons The Euxopean CommJLLee fox Standaxdnzahon s eaued CEN WWW Cenoxm bel whose mlsslon s to pxomote Voluntazy teehmea1 haxmomzahon 1n Euxope 1n Comunchon mth woxldWJde agencles and Ls Euxopean paxtnexs The puzposes nclude the loweung of made baulezs and the pxomohon of Common teehmea1 undezstandnng Euxopean standazds ex ESI tom UK and DJN tom Gezmany may be accessed ma CEN The Japanese Standazds Assoclahon WWW153 011p a1so has extenswe hshngs ANSI eAmenean Nabonal Standazds 1nsntute The US xepzesentahve fox ISO the 1ntemahona1 Standazds Oxgamzahon WWW ans 01g C78 4071986 Speemeatmns fax Malnury 1amps C78180e1989 Speemeatmns fax FlunzescenLLamp Stanaxs C78 37671991 Guxde fax E1eetnea1 Measuzements DfFluuzesnenLLamps C78 386 Menu Lamps 7 Measuzement nfChaxacLeusLms C78 387 Metaeralxde Lamps 7 MeasuzememDfChazanIEusLms C78 388 H1 h Flessuxe Sndmm Lamps 7 Measuzement nfChaxacLeusLms C821e1986 Speemeatmns fax FluuzesnenLLampEallasLs C82 Here 1990 Speemeatmns fax FluuzescenLLampEallasLs Supplement h C82 1 C82 371989 Speemeatmns fax Fluuzesnem Lamp Refezenne Eauasts C82 419 Speemeatmns fax ngh 1ntens1ty stchazge and Law Flessuxe Sndmm amp Eauasts C82 671990 Speemeatmns fax nghrlntensxtyerschazge Lamp Refezenne Eauasts C82 671986 Metheds DfMeasuxemenL nfstchax e Lamp Eauasts ANSINCSL Ameuean Natmnal Standade fax Calxbxauun e Calxbxauun 5407171994 Lahmateues and Measuxmg and Test Eqmpmente Genezal Requuements ANSIES R1116 Amenean Nabonal Standaxd Nomene1atme and Dehmnons fox Ulummahng Engineeung 1986 ASTM The Amenean somety fox Teshng and Matena1s WWW astm 01g mmntmns an extenswe eoueehon of pzotocol oz documentaxy standaxds nCludJng pxaChCes specl cahons guldes pzoceduxes and test methods fox a laxge xange ofmatena1s and mstmmentanon fox then Chazacteuzahon some 10000 standaxds axe pubhshed annuauy n a 7aevo1ume set ofwhmh one Volume 5 the ndex alone The ASTM Book of Standazds occuples neaxly 2 metexs of shelf space These documean are subject to periodic review and revision by the committees that were responsible for their generation and maintenance Always check at wwwastmorg to see if a later verions is available A number of these standards are the result of the efforts of committee E12 on Color and Appearance committee E20 on Temperature Measurement and committee E87 on Thermal Measurement Special collections in specific areas are also published For example ASTM Standards on Color and Appearance Measurement Sixth Edition 2000 This book contains 108 ASTM standards as well as ISO and ISOCIE standards used in appearance analysis for a variety of materials and products including all the standards listed above Includes a CDROM with even more information The following listing shows a selection of relevant standards to radiometry photometry and colorimetry Another useful guide is quotNomenclature and Definitions Applicable to Radiometric and Photometric Characteristics of Matter ASTM Special Technical Publication 475 1971 Guide for Recommended Uses of Photoluminescent Safety Markings ASTM E2080 1999 Specification for Photoluminescent Safety Markings ASTM Z6474Z Standard Practice for Preparation of Pressed Powder White Re ectance Factor Transfer Standards for Hemispherical Geometry and BiDirectional Geometriesquot ASTM E259 1998 Recommended Practice for Goniophotometry of Objects and Materialsquot ASTM E167 1996 Specification for Daytime Pedestrian Visibility Enhancement ASTM E 1896 1997 Standard Guide for Describing and Specifying the Spectrometer of an Optical Emission Direct Reading Instrument ASTM E1507 1998 Standard Guide for Designing and Conducting Visual Experiments ASTM E 1808 1996 Standard Guide for Establishing Spectrophotometer Performance Tests ASTM E 1866 1997 Standard Guide to Evaluation of Optical Properties of Powder Coatings ASTM D5882 1995 Standard Guide for Examining Electrical and Mechanical Equipment with Infrared Thermography ASTM E1984 1999 Standard Guide for Modeling the Colorimetric Properties of a Visual Display Unit ASTM E1682 200 1 Standard Guide for Preparation Maintenance and Distribution of Physical Product Standards for Color and Geometric Appearance of Coatings ASTM D5581 1999 Standard Guide for Quality Assurance of Laboratories Using Molecular Spectroscopy ASTM E924 1994 Standard Guide for Quantitative Analysis by EnergyDispersive Spectroscopy ASTM E 1508 1998 Standard Guide for Raman Shiftquot ASTM E1840 1996 Standard Guide for Selection of Geometric Conditions for Measurement of Re ection and Transmission Properties of Materials ASTM E179 1996 Standard Guide for Use of Lighting in Laboratory Testing ASTM E1788 1995 Standard Guide to Evaluation of Optical Properties of Powder Coatings ASTM D5882 1995 Standard Guide to Properties of High Visibility Materials Used to Improve Individual Safety ASTM F928 2000 Standard Method for Calibration of Reference Pyranometers With Axis Vertical by the Shading Method ASTM E918 1999 quotStandard Practice for Angle Resolved Optical Scatter Measurements on Specular or Diffuse Surfaces ASTM E1392 1996 Standard Practice for Calculating Solar Reflectance Index of Horizontal and LowSloped Opaque Surfaces ASTM E1980 2001 Standard Practice for Calculating Yellowness and Whiteness lndices from lnstrumentally Measured Color Coordinates ASTM E313 2000 Standard Practice for Calculation of Photometric Transmittance and Re ectance of Materials to Solar Radiation ASTM E971 1996 Standard Practice for Calculation of Weighting Factors for Tristimulus Integration ASTM E2022 200 1 Standard Practice for Calibrating Thin Heat Flux Transducers ASTM C1130 2001 Standard Practice for Calibration of Ozone Monitors and Certification of Ozone Transfer Standards Using Ultraviolet Photometry ASTM D5110 1998 Standard Practice for Calibration of the Heat Flow Meter Apparatus ASTM C1132 1995 Standard Practice for Calibration of Transmission Densitometers ASTM E1079 2000 Standard Practice for Calculating Yellowness and Whiteness lndices from lnstrumentally Measured Color Coordinates ASTM E313 2000 Standard Practice for Color Measurement of Fluorescent Specimens ASTM E991 1998 Standard Practice for Computing the Colors of Fluorescent Objects from Bispectral Photometric Data ASTM E2152 2001 Standard Practice for Computing the Colors of Objects by Using the CIE System ASTM E308 1999 Standard Practice for Describing and Measuring Performance of Dispersive lnfrared Spectrometers ASTM E932 1997 Standard Practice for Describing and Measuring Performance of Fourier Transform MidInfrared FTMlR Spectrometers Level Zero and Level One Tests ASTM E1421 1999 Standard Practice for Describing and Measuring Performance of Laboratory Fourier Transform NearInfrared FTNlR Spectrometers Level Zero and Level One Tests ASTM E1944 1998 Standard Practice for Describing and Measuring Performance of Ultraviolet Visible and Near lnfrared Spectrophotometers ASTM E275 2001 Standard Practice for Describing and Specifying InductivelyCoupled Plasma Atomic Emission Spectrometers ASTM E1479 1999 Standard Practice for Describing Photomultiplier Detectors in Emission and Absorption Spectrometry ASTM E520 1998 Standard Practice for Describing Retroreflection ASTM E808 1999 Standard Practice for Determining the Steady State Thermal Transmittance of Fenestration Systems ASTM E1423 1999 Standard Practice for Electronic lnterchange of Color and Appearance Data ASTM E1708 2001 Standard Practice for Establishing Color and Gloss Tolerances ASTM D3134 1997 Standard Practice for Evaluating Solar Absorptive Materials for Thermal Applications ASTM E744 1996 Standard Practices for General Techniques of UltravioletVisible Quantitative Analysis ASTM E 169 1999 Standard Practice for Goniophotometry of Objects and Materials ASTM E167 1996 A47 Standard Practice for Identification of Instrumental Methods of Color or ColorDifference Measurement of Materials ASTM E805 2001 Standard Practice for Measuring Colorimetric Characteristics of Retrore ectors Under Nighttime Conditions ASTM E81 1 2001 Standard Practice for Measuring Photometric Characteristics of Retrore ectorsquot ASTM E809 2000 Standard Practice for Measuring Practical Spectral Bandwidth of UltravioletVisible Spectrophotometers ASTM E958 1999 Standard Practice for Near Infrared Qualitative Analysis ASTM E 1790 2000 Standard Practice for Obtaining Bispectral Photometric Data for Evaluation of Fluorescent Color ASTM E2153 2001 Standard Practice for Obtaining Colorimetric Data from a Visual Display Unit Using Tristimulus Colorimetersquot ASTM E1455 1997 Standard Practice for Obtaining Spectrophotometric Data for ObjectColor Evaluation ASTM E 1 164 1994 Standard Practice for Obtaining Spectroradiometric Data from Radiant Sources for Colorimetry ASTM E1341 2001 Standard Practice for Preparation of Pressed Powder White Reflectance Factor Transfer Standards for Hemispherical Geometry and BiDirectional Geometriesquot ASTM E259 1998 Standard Practice for Preparation of Textiles Prior to Ultraviolet UV Transmission Testing ASTM D6544 2000 Standard Practice for Qualifying Spectrometers and Spectrophotometers for Use in Multivariate Analyses Calibrated Using Surrogate Mixtures ASTM E2056 2000 Standard Practice for Reducing the Effect of Variability of Color Measurement by Use of Multiple Measurements ASTM E1345 1998 Standard Practice for Selecting and Calibrating Sources for the Visual Assessment of Object Colors ASTM Z6606Z Standard Practice for Selection and Use of Portable Retrore ectomers for the Measurement of Pavement Marking Materials ASTM E 1743 1996 Standard Practice for Solar Simulation for Thermal Balance Testing of Spacecraft ASTM E491 1999 Standard Practice for Specifying and Matching Color Using the Colorcurve System ASTM E 1541 1998 Standard Practice for Specifying and Verifying the Performance of Colorimeters Spectrocolorimeters and Goniospectrocolorimetersquot ASTM Z6899Z Standard Practice for Specifying Color by the Munsell System ASTM D1535 2001 Standard Practice for Specifying Color by Using the Optical Society of America Uniform Color Scales System ASTM E1360 2000 Standard Practice for Specifying the Geometry of Observations and Measurements to Characterize the Appearance of Materials ASTM E 1767 1995 Standard Practice for the Periodic Calibration of Narrow BandPass Spectrophotometers ASTM E925 1994 Standard Practice for Testing FixedWavelength Photometric Detectors Used in Liquid Chromatography ASTM E685 2000 Standard Practice for Testing VariableWavelength Photometric Detectors Used in Liquid Chromatography ASTM E1657 2001 Standard Practice for Transfer Standards for Re ectance Factor for NearInfrared Instruments Using Hemispherical Geometry ASTM E1791 2000 Standard Practice for Validation of Multivariate Process Infrared Spectrophotometers ASTM D6122 1999 Standard Practice for Visual Appraisal of Colors and Color Differences of DiffuselyIlluminated Opaque Materials ASTM D1729 1996 Standard Practice for Visual Color Evaluation of Transparent Sheet Materials ASTM E1478 1997 Standard Practice for Visual Evaluation of Metamerism ASTM D4086 1997 Standard Practices for General Techniques of UltravioletVisible Quantitative Analysis ASTM E 169 1999 Standard Practices for Infrared Multivariate Quantitative Analysis ASTM E1655 2000 Standard Practices for Internal Reflection Spectroscopy ASTM E573 2001 Standard Solar Constant and Zero Air Mass Solar Spectral Irradiance Tables ASTM E490 2000 Standard Specification for Infrared Thermometers for Intermittent Determination of Patient Temperaturequot ASTM E1965 1998 Standard Specification for Nighttime Photometric Performance of Retrore ective Pedestrian Markings for Visibility Enhancementquot ASTM E 1501 1999 Standard Specification for Photoluminescent Phosphorescent Safety Markings ASTM E2072 2000 Standard Specification for Physical Characteristics of Nonconcentrator Terrestrial Photovoltaic Reference Cellsquot ASTM E1040 1998 Standard Specification for Retroreflective Sheeting for Traffic Control ASTM D4956 2001 Standard Specification for Silvered Flat Glass Mirror ASTM C1503 2001 Standard Specification for Solar Simulation for Terrestrial Photovoltaic Testing ASTM E927 1997 Standard Tables for References Solar Spectral Irradiance at Air Mass 15 Direct Normal and Hemispherical for a 37 Tilted Surface ASTM G159 1998 Standard Terminology of Appearance ASTM E284 2001 Standard Terminology Relating to Molecular Spectroscopy ASTM E 131 2000 Standard Terminology Relating to Photovoltaic Solar Energy Conversionquot ASTM E 1328 1999 Standard Terminology Relating to Solar Energy Conversion ASTM E772 1993 Standard Test Method for 20deg Specular Gloss of Waxed Paperquot ASTM D1834 2000 Standard Test Method for 45deg Specular Gloss of Ceramic Materials ASTM C346 1998 Standard Test Method for 60deg Specular Gloss of Emulsion Floor Polish ASTM D1455 1997 Standard Test Method for Assessing the Quality of Sources for the Visual Assessment of Object Colors quot ASTM Z6607Z Standard Test Method for Calibration of a Spectroradiometer using a Standard Source of Irradiance ASTM G138 1996 Standard Test Method for Calibration of Heat Transfer Rate Calorimeters using a NarrowAngle Blackbody Radiation Facility ASTM E638 1992 Standard Test Method for Calibration of Narrow and Broadband Ultraviolet Radiometers using a Spectroradiometer ASTM G130 1995 quotStandard Test Method for Calibration of a Pyranometer Using a Pyrheliometer ASTM G151 2000 Standard Test Method for Color and ColorDifference Measurement by Tristimulus Filter Colorimetryquot ASTM E1347 1997 formerly E97 Standard Test Method for Determining the Linearity of a Photovoltaic Device Parameter With respect to a Test Parameter ASTM E1143 1994 Standard Test Method for Estimating Stray Radiant Power Ratio of Spectrophotometers by the Opaque Filter Method ASTM E387 1995 Standard Test Method for Field Measurement of Raised Retrore ective Pavement Markers Using a Portable Retrore ectometer ASTM E 1696 2001 Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics ASTM D1003 2000 Standard Test Method for Identifying Fluorescence in ObjectColor Specimens by Spectrophotometryquot ASTM E1247 2000 Standard Test Method for Luminous Re ectance Factor of Acoustical Materials by Use of IntegratingSphere Re ectometers ASTM E1477 1998 Standard Test Method for Measuring and Calculating Emittance of Architectural Flat Glass Products Using Spectrometric Measurements ASTM E1585 1993 Standard Test Method for Minimum Detectable Temperature Difference for Thermal Imaging Systems ASTM E1311 1999 Standard Test Method for Noise Equivalent Temperature Difference of Thermal Imaging Systems ASTM E 1543 2000 Standard Test Method for Obtaining Colorimetric Data From a Visual Display Unit by Spectroradiometry ASTM E 1336 1996 Standard Test Method for Obtaining Colorimetric Data from a Visual Display Unit Using Tristimulus Colorimetersquot ASTM E 1455 1997 Standard Test Method for Obtaining Spectroradiometric Data From Radiant Sources for Colorimetryquot ASTM E 1341 1996 Standard Test Method for Photopic Luminance of Photoluminescent Phosphorescent Markings ASTM E2073 2000 Standard Test Method for Radiation Thermometer Single Waveband Type ASTM E1256 1988 Standard Test Method for Re ection Haze of HighGloss Surfaces ASTM D4039 1999 Standard Test Method for Re ectance Factor and Color by Spectrophotometry Using Bidirectional Geometry ASTM E1349 1998 Standard Test Method for Solar Absorptance Re ectance and Transmittance of Materials Using Spectrophotometers With Integrating Spheres ASTM E903 1988 Standard Test Methods for Solar Energy Transmittance and Re ectance Terrestrial of Sheet Materialsquot ASTM E424 1993 Standard Test Method for Solar Absorptance Re ectance and Transmittance ofMaterials Using Integrating Spheres ASTM E903 1996 Standard Test Method for Spectral Bandwidth and Wavelength Accuracy of Fluorescence Spectrometers ASTM E388 1998 Standard Test Method for Specular Gloss ASTM D523 1999 Standard Test Method for Specular Gloss of Paper and Paperboard at 75 ASTM D1223 1998 Standard Test Method for Total Luminous Reflectance Factor by Use of 30T IntegratingSphere Geometry ASTM E1651 1999 Standard Test Method for Transfer of Calibration From Reference to Field Radiometers ASTM E824 1994 Standard Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry ASTM E1348 1996 Standard Test Method for Transparency of Plastic Sheeting ASTM D1746 1997 Standard Test Method for Visual Evaluation of Gloss Differences Between Surfaces of Similar Appearance ASTM D4449 1999 Standard Test Method for Total Hemispherical Emittance of Surfaces From 20 to 1400 C ASTM C835 2000 Standard Test Method for Brightness of Pulp Paper and Paperboard Directional Re ectance at 457 nm ASTM D985 1997 Standard Test Method for Calculation of Color Differences From lnstrumentally Measured Color Coordinatesquot ASTM D2244 2000 Standard Test Method for Calibration of Pyrheliometers by Comparison to Reference Pyrheliometers ASTME816 1995 Standard Test Method for Calibration of a Pyranometer Using a Pyrheliometer ASTM G167 2000 Standard Test Method for Calibration of a Spectroradiometer Using a Standard Source of lrradiance ASTM G138 1996 Standard Test Method for Calibration of Narrow and BroadBand Ultraviolet Radiometers Using a Spectroradiometer ASTM G130 1995 Standard Test Method for Calibration of Primary NonConcentrator Ter39restr39ial Photovoltaic Reference Cells Using a Tabular Spectrum ASTM E1125 1999 Standard Test Method for Calibration of Reference Pyranometers With Axis Tilted by the Shading Methodquot ASTME941 1999 Standard Test Method for Calibration of Silicon NonConcentrator Photovoltaic Pr39imary Reference Cells Under Global Irradiationquot ASTM E1039 1999 Standard Test Method for Calorimetr39ic Determination of Hemispherical Emittance and the Ratio of Solar Absorptance to Hemispherical Emittance Using Solar Simulation ASTM E434 1996 Standard Test Method for Coefficient of Retrore ection of Retrore ective Sheeting Utilizing the Coplanar Geometry ASTM E810 2001 Standard Test Method for Color and ColorDifference Measurement by Tristimulus Filter Color39imetryquot ASTM E 1347 1997 Standard Test Method for Color of Liquids Using Tr39istimulus Colorimetry ASTM D5386 2000 Standard Test Method for Conducting Aqueous Direct Photolysis Tests ASTM E896 1997 Standard Test Method for Detecting Delaminations in Br39idge Decks Using lnfrared Thermography ASTM D4788 1997 Standard Test Method for Determining Solar or Photopic Reflectance Transmittance and Absorptance of Materials Using a Large Diameter Integrating Spherequot ASTM E1175 1996 Standard Test Method for Determining the Linearity of a Photovoltaic Device Parameter With Respect To a Test Parameter ASTM E1143 1999 Standard Test Method for Diffuse Light Transmission Factor of Reinforced Plastics Panels ASTM D1494 1997 Standard Test Method for Electrical Performance of Photovoltaic Cells Using Reference Cells Under Simulated Sunlight ASTM E948 1995 Standard Test Method for Evaluating Color Image Output from Color Printers and Copiers ASTM F1206 2000 Standard Test Method for Evaluation of Color for Thermoplastic Traffic Marking Materials ASTM D4960 1998 Standard Test Method for Evaluation of Visual Color Difference With a Gray Scale ASTM D2616 1996 Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics ASTM D1003 2000 Standard Test Method for Hiding Power of Paints by Re ectometryquot ASTM D2805 1996 Standard Test Method for Identifying Fluorescence in ObjectColor Specimens by Spectrophotometryquot ASTM E 1247 2000 Standard Test Method for Linearity of Fluorescence Measuring Systems ASTM E578 2001 Standard Test Method for Luminous Re ectance Factor of Acoustical Materials by Use of IntegratingSphere Re ectometers ASTM E1477 1998 Standard Test Method for Measuring TotalRadiance Temperature of Heated Surfaces Using a Radiation Pyrometer ASTM E639 1996 Standard Test Method for Measurement and Calculation of Re ecting Characteristics of Metallic Surfaces Using Integrating Sphere Instruments ASTM E429 Standard Test Method for Measurement of HighVisibility Retrore ectiveClothing Marking Material Using a Portable Retrorelectometerquot ASTM E1809 1996 Standard Test Method for Measurement of Retrore ective Pavement Marking Materials With CEN Prescribed Geometry Using a Portable Retrore ectometer ASTM E1710 1997 Standard Test Method for Measurement of Retrore ective Signs Using a Portable Retrore ectometer ASTM E 1709 2000 Standard Test Method for Minimum Detectable Temperature Difference for Thermal Imaging Systems ASTM E 131 1 1999 Standard Test Method for Minimum Resolvable Temperature Difference for Thermal Imaging Systems ASTM E 1213 1997 Standard Test Method for Noise Equivalent Temperature Difference of Thermal Imaging Systems ASTM E 1543 2000 Standard Test Method for Normal Spectral Emittance at Elevated Temperaturesquot ASTM E307 1996 Standard Test Method for Normal Spectral Emittance at Elevated Temperatures of Nonconducting Specimens ASTM E423 1996 Standard Test Method for Obtaining Colorimetric Data From a Visual Display Unit by Spectroradiometry ASTM E1336 1996 Standard Test Method for Opacity of Paper 15 Diffuse Illuminant A 89 Re ectance Backing and Paper Backingquot ASTM D589 1997 Standard Test Method for PhotoeIastic Measurements of Birefringence and Residual Strains in Transparent or Translucent Plastic Materials ASTM D4093 1995 Standard Test Method for Re ectance Factor and Color by Spectrophotometry Using Hemispherical Geometry ASTM E1331 1996 Standard Test Method for Re ectance Factor and Color by Spectrophotometry Using Bidirectional Geometry ASTM E1349 1998 Standard Test Method for Re ection Haze of HighGloss Surfaces ASTM D4039 1999 Standard Test Method for Relative Tinting Strength of Aqueous Ink Systems by Instrumental Measurement ASTM D6531 2000 Standard Test Method for Relative Tinting Strength of White Pigments by Re ectance Measurements ASTM D2745 2000 Standard Test Method for Retrore ectance of Horizontal Coatings ASTM D4061 2000 Standard Test Method for Solar Absorptance Re ectance and Transmittance of Materials Using Integrating Spheres ASTM E903 1996 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight ASTM E972 1996 Standard Test Method for Solar Transmittance Terrestrial of Sheet Materials Using Sunlightquot ASTM E1084 1996 Standard Test Method for Spectral Bandwidth and Wavelength Accuracy of Fluorescence Spectrometers ASTM E388 1998 Standard Test Method for Specular Gloss ASTM D523 1999 Standard Test Method for Specular Gloss of Glazed Ceramic Whitewares and Related Products ASTM C584 1999 Standard Test Method for Total Luminous Re ectance Factor by Use of 30t Integrating Sphere Geometry ASTM E1651 1999 Standard Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry ASTM E1348 1996 Standard Test Method for Transparency of Plastic Sheeting ASTM D1746 1997 Standard Test Methods for Continuous Measurement of Ozone in Ambient Workplace and Indoor Atmospheres Ultraviolet Absorption quot ASTM D5156 1995 Standard Test Methods for Measurement of Gloss of HighGloss Surfaces by Goniophotometry ASTM E430 1997 Standard Test Methods for Measuring and Compensating for Emissivity Using Infrared Imaging Radiometers ASTM E1933 1999 quotStandard Test Methods for Measuring and Compensating for Re ected Temperature Using Infrared Imaging Radiometers ASTM E 1862 1997 Standard Test Methods for Measuring and Compensating for Transmittance of an Attenuating Medium Using Infrared Imaging Radiometers ASTM E 1897 1997 Standard Test Methods for Measuring Optical Re ectivity of Transparent Materials ASTM E1682 1996 Standard Test Methods for Measuring Spectral Response of Photovoltaic CeIIs ASTM E 1021 1995 Standard Test Methods for Measuring TotalRadiance Temperature of Heated Surfaces using a Radiation Pyrometerquot ASTM E639 1990 Standard Test Methods for Measurement of Gloss of HighGloss Surfaces by Goniophotometry ASTM E430 1997 Standard Test Methods for Minimum DetectabIe Temperature Difference for Thermal Imaging Systems ASTM E 1311 1993 Standard Test Methods for Minimum ResoIvabIe Temperature Difference for Thermal Imaging Systems ASTM E 1213 1992 Standard Test Methods for Noise Equivalent Temperature Difference of Thermal Imaging Systems ASTM E 1543 1994 Standard Test Methods for Radiation Thermometers Single Waveband Type ASTM E1256 1995 Standard Test Methods for Solar Energy Transmittance and Reflectance Terrestrial of Sheet Materials ASTM E424 1993 Standard Test Methods for Total Normal Emittance of Surfaces Using InspectionMeter Techniques ASTME408 1996 BIPM The BIPM Bureau International des Poids et Mesures WWWbi mfr is an international institute operating under the supervision of the Comite International des Poids et Mesures CIPM It is charged with the establishment and maintenance of reference standards the organization of international comparisons and carrying out of calibrations and fundamental investigations that may result in better reference standards or measurement techniques The prototype kilogram is located here Some of their publications include Principles Governing Photometry 1983 The International System of Units SI BIPM 7th Edition 1998 Supplementary Information for the International Temperature Scale of 1990 BIPM 1990 Chapter 6 Radiation Thermometry International Vocabulary of Basic and General Terms in Metrology joint BIPM IEC IFCC ISO IUPAC IUPAP OIML Standard 1993 Guide to the Expression of Uncertainty in Measurement joint BIPM IEC IFCC ISO IUPAC IUPAP OIML Standard 1993 CIE The Commission Internationale Q L39Eclairage WWWciecoatciel has numerous Technical Committee Reports that are relevant Write to Thomas Lemons TLA Lighting Consultants Inc 7 Pond St Salem MA 01970 or call 508 7456870 FAX 508 7414420 for a listing of current publications and pricing Check into their web page for more information Division 1 at httpnmlcsircozacie1 is involved with Vision and Colour While Division 2 at httpcie2nistgov deals with the Measurement of Light and Radiation The US National Committee of the CIE is at httpwwwcieusncorg Some pertinent reports primarily from Division 2 are 133 Method of measuring and specifying colour rendering of light sources 1995 152 174 182 38 41 44 46 53 54 59 63 64 65 69 70 75 76 78 81 84 85 86 87 96 105 114 121 125 Colorimetry 2nd ed 1986 International lighting vocabulary 4th ed Joint publication lECCIE 1987 The basis of physical photometry 2nd ed 1983 Radiometric and photometric characteristics of materials and their measurement 1977 Light as a true visual quantity Principles of measurement 1978 Absolute methods for re ection measurements 1979 A review of publications on properties and reflection values of material re ection standards 1979 Methods of characterizing the performance of radiometers and photometers 1982 Retroreflection Definition and measurement 2001 Polarization Definitions and nomenclature instrument polarization 1984 The spectroradiometric measurement of light sources 1984 Determination of the spectral responsivity of optical radiation detectors 1984 Electrically calibrated thermal detectors of optical radiation absolute radiometers 1985 Methods of characterizing illuminance meters and luminance meters Performance characteristics and specifications 1987 The measurement of absolute luminous intensity distributions 1987 Spectral luminous efficiency functions based upon brightness matching for monochromatic point sources 20 and 100 fields 1988 lntercomparison on measurement of total spectral radiance factor of luminescent specimens 1988 Brightnessluminance relations Classified bibliography 1988 Mesopic photometry History special problems and practical solutions 1989 Measurement of luminous fluX 1989 Solar spectral irradiance 1989 CIE 1988 2 spectral luminous efficiency function for photopic vision 1990 Colorimetry of selfluminous displays A bibliography 1990 Electric light sources State of the art 1991 1992 Spectroradiometry of pulsed optical radiation sources 1993 CIE Collection in Photometry and Radiometry 1994 The Photometry and Goniophotometry of Luminaires 1996 Standard Erythema Dose a Review 1997 A55 127 Measurement of LEDs 1997 130 Practical Methods for the Measurement of Re ectance and Transmittance 1998 141 Testing of Supplementary Systemsof Photometry 2001 IES The Illuminating Engineering Society of North America IESNA 1wwwiesnaorgb has an extensive list of publications dealing with illumination Their IESNA Lighting Handbook Ninth Edition is the definitive reference The following are procedures dealing with photometric measurements of varoius lamps and luminaires LM9 Electrical amp Photometric Measurements of Fluorescent Lamps LM10 Photometric Testing of Outdoor Fluorescent Luminaires LM11 Photometric Testing of Searchlights LM20 Photometric Testing of Re ectorType Lamps LMSl Photometric Testing of Roadway Luminaires LM35 Photometric Testing of Floodlights Using HighIntensity Discharge Lamps or Incandescent Filament Lamps LM41 Photometric Testing of Indoor Fluorescent Luminaires LM44 Method for Total and Diffuse Re ectometry 1985 LM45 Electrical and Photometric Measurements of General Service Incandescent Filament Lamps LM46 Photometric Testing of Indoor Luminaires Using HID Discharge or Incandescent Filament Lamps LM50 Photometric Measurement of Roadway Lighting Installations LM51 Electrical and Photometric Measurements of HighIntensity Discharge Lamps LM52 Photometric Measurement of Roadway Sign Installations LM54 Lamp Seasoning LM55 Measurement of Ultraviolet Radiation from Light Sources LM58 Spectroradiometric Measurements LM59 Electrical and Photometric Measurements of LowPressure Sodium Lamps LM63 Standard File Format for Electronic Transfer of Photometric Data LM64 Photometric Measurements of Parking Areas LM66 Electrical and Photometric Measurements of Compact Fluorescent Lamps LM68 Photometric Evaluation of Vehicle Traffic Control Signal Heads LM70 NearField Photometry LM72 Directional Positioning of Photometric Data RP16 Nomenclature and Definitions for Illuminating Engineering ANSI Approved ISO The International Standards Organization wwwisoch ISO 2470 Brightness for Fluorescent Materials 1999 ISOCIE 10526 CIE standard illuminants for colorimetry CIE S005E1998 1999 ISOCIE 10527CIE standard colorimetric observers CIE S002 1986 1991 ISOCIE 15469 Spatial distribution of daylight CIE standard overcast sky and clear sky CIE S008 1996 1997 ISOCIE 16508 Road traffic lights Photometric properties of 200mm round signals CIE S006 1999 ISOl7166 Erythema reference action spectrum and standard erythema dose CIE S007 1999 ISO 11475 Paper and board Determination of CIE whiteness D6510 degrees outdoor daylight 1999 ISO 11476 Paper and board Determination of CIEWhiteness C2 degrees indoor illumination conditions 2000 ISO 8599 Optics and optical instruments Contact lenses Determination of the spectral and luminous transmittance1994 ISO 98451 Solar energy Reference solar spectral irradiance at the ground at different receiving conditions Part 1 Direct normal and hemispherical solar irradiance for air mass 15 1992 ISO 90229 Optics and optical instruments Environmental test methods Part 9 Solar radiation 1994 ISO 902217 Optics and optical instruments Environmental test methods Part 17 Combined contamination solar radiation 1994 ISO 9050 Glass in building Determination of light transmittance solar direct transmittance total solar energy transmittance and ultraviolet transmittance and related glazing factors 1990 ISO 9059 Solar energy Calibration of field pyrheliometers by comparison to a reference pyrheliometer 1990 ISO 9060 Solar energy Specification and classification of instruments for measuring hemispherical solar and direct solar radiation 1990 ISO 9488 Solar energy Vocabulary 1999 ISO 98451 Solar energy Reference solar spectral irradiance at the ground at different receiving conditions iPart 1 Direct normal and hemispherical solar irradiance for air mass 15 1992 ISO 9846 Solar energy Calibration of a pyranometer using a pyrheliometer 1993 ISO 9847 Solar energy Calibration offield pyranometers by comparison to a reference pyranometer 1992 ISOTR 9901 Solar energy Field pyranometers Recommended practice for use 1990 ISO 6 Photography BlackandWhite pictorial still camera negative filmprocess systems Determination of ISO speed 1993 ISO 2240 Photography Colour reversal camera films Determination ofISO speed 1994 ISO 8478 Photography Camera lenses Measurement of ISO spectral transmittance 1996 ISO 12232 Photography Electronic stillpicture cameras Determination of ISO speed 1998 IEC International Electrotechnical Commission Founded in 1906 the International Electrotechnical Commission IEC is the world organization that prepares and publishes international standards for all electrical electronic and related technologies The IEC was founded as a result of a resolution passed at the International Electrical Congress held in St Louis USA in 1904 The membership consists of more than 50 participating countries including all the world39s major trading nations and a growing number of industrializing countries IEC 6196621 Multimedia systems and equipment Colour measurement and management Ed 1 1999 Part 21 Colour management Default RGB colour space sRGB IEC 619663 Multimedia systems and equipment Colour measurement and management Ed 1 2000 Part 3 Equipment using cathode ray tubes IEC 619664 Multimedia systems and equipment Colour measurement and management Ed 1 2000 Part 4 Equipment using liquid crystal display panels IEC 619665 Multimedia systems and equipment Colour measurement and management Ed 1 2000 Part 5 Equipment using plasma display panels IEC 619668 Multimedia systems and equipment Colour measurement and management Ed 1 2001 Part 8 Multimedia colour scanners IEC 619669 Multimedia systems and equipment Colour measurement and management Ed 1 2000 Part 9 Digital cameras 3 rue de Varembe Tel 4122 919 02 11 PO BOX 131 Fax 41 22 919 03 00 1211 Geneva 20 Web site httpwwwiecch Switzerland NVLAP National Voluntary Laboratory Accreditation Program Established in 1976 and administered by the National Institute of Standards and Technology NIST NVLAP is an unbiased governmentbased third party system for accrediting calibration laboratories and testing laboratories found competent to perform specific tests or calibrations Criteria for NVLAP accreditation are published in the Code Federal Regulations Title 15 Part 285 and encompass the requirements of ISOIES Guide 25 and the relevant requirements of ISO 9002 NVLAP accreditation is available to commercial laboratories manufacturers39 inhouse laboratories university laboratories federal state and local government laboratories and foreignbased laboratories NIST Handbook 150 National Voluntary Laboratory Accreditation Program NVLAP Procedures and General Requirements J L Cigler and V R White March 1994 NIST Handbook 1501 National Voluntary Laboratory Accreditation Program NVLAP Energy Efficient Lighting Products L S Galowin W Hall and W J Rossiter Jr July 1994 NlST Handbook 1502 DRAFT National Voluntary Laboratory Accreditation Program NVLAP Calibration Laboratories Technical Guide J M Crickenberger ed reprinted Dec 1997 Handbook 150 and 1501 are available on the NVLAP website at http WWW ts nist govnvlap NVLAP identifies its accredited laboratories in a published directory NIST Special Publication 810 and on their web site National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program 100 Bureau Drive MS 2140 Gaithersburg Maryland 208992140 Telephone 3019754016 Fax 3019262884 EMail NVLAPnistgov Website httpWWWtsnistgovnvlap SAE Society of Automotive Engineers WWWsaeor is a nonprofit educational and scientific organization dedicated to advancing mobility technology to better serve humanity Nearly 70000 engineers and scientists Who are SAE members develop technical information on all forms of selfpropelled vehicles including automobiles trucks and buses offhighway equipment aircraft aerospace vehicles marine rail and transit systems SAE disseminates this information through meetings books technical papers magazines standards reports professional development programs and electronic databases Here is a selection of their relevant standards mostly dealing With lighting and its measurement HS34 SAE Ground Vehicle Lighting Standards Manual 1999 J387 Terminology Motor Vehicle Lighting 1995 J1330 Photometry Laboratory Accuracy Guidelines 1994 J 575 Test Methods and Equipment for Lighting Devices and Components for Use on Vehicles Less than 2032 mm in Overall Width 1992 J 1383 Performance Requirements for Motor Vehicle Headlamps 1996 J2217 Photometric Guidelines for Instrument Panel Displays that Accommodate Older Drivers 199 1 TAPPI TAPPI is the leading technical association for the worldwide pulp paper and converting industry TAPPI provides its members rapid access to 1 the largest international group of technically eXperienced people in the industry 2 the most comprehensive collection of reliable technical information and knowledge in the industry and 3 the highest quality products and services created to meet the needs of people who solve technical problems in the industry Among their documentary standards are the following T425 Opacity of Paper 15d geometry Illuminant A2 89 Re ectance T452 Brightness of Pulp Paper and Paperboard Directional Re ectance at 457 nm T480 Specular Gloss of Paper and Paperboard at 75 1999 T560 CIE Whiteness and Tint of Paper and Paperboard Using d0 Diffuse Illumination and Normal Viewing T562 CIE Whiteness and Tint of Paper and Paperboard Using 45 l0 Directional Illumination and Normal Viewing T1209 Identification of Instrumental Methods of Color or Color Difference Measurement T1212 Light Sources for Evaluating Papers Including Those Containing Fluorescent Whitening Agents T1213 Optical Measurements Terminology Related to Appearance Evaluation of Paper T1214 Interrelation of Re ectance Ro TAPPI Opacity Co 89 Scattering s and Absorption k T1215 The Determination of Instrumental Color Differences T1216 Indices for Whiteness Yellowness Brightness and Luminous Re ectance Factor T1217 Photometric Linearity of Optical Properties Instruments T1218 Calibration of Re ectance Standards for Hemispherical Geometry http www tappiorg APPENDIX IX RADIOMETRY AND PHOTOMETRY ON THE INTERNET Hop on the Internet and start surfing The World Wide Web W W W or W3 gets larger and hopefully more educational every day The following list includes some of the sites that I have found useful and informative OPTICS RADIOMETRY PHOTOMETRY STUFF OSA OpticsNet SPIE HOME PAGE RADIOMETRY by MP my page NIST Optical Physics NIST Boulder NPL CSIRO Australia NRC Canada PTB Germany CORM International Commission on Illumination CIE Infrared Information Analysis Center IRIA IEEE Home Page University of Arizona Remote Sensing Remote Sensing Data and Information USU Space Dynamics Laboratory AIP American Institute of Physics ANSI American Nat39l Standards Institute ASTM BIPM International Bureau of Weights and Measures Color Vision Lab at UCSD IESNA Illuminating Engineering Society of North America ISO International Standards Organization IUPAP International Union of Pure and Applied Physics WWWosaorg WWWspieorg WWWopticsArizonaeduP almer WWWphysicsnistgov WWWbouldernistgovdiv8 15 WWWnplcouk WWWdap csiro au WWWcorpservnrccacorpserv WWWptbldeenglishWelcomehtml WWWcormorg WWWcieco atcie WWWerim orgIRIAiriahtmlquot WWWieeeorg WWW opticsArizonaedursg WWWrsdgsfc nasagovrsdRemoteSen singhtml WWWcalsdlusuedu WWW aip org WWW ansiorg WWW astm org WWWbipm fr cvisionuscdedu WWWiesnaorg WWWisoch WWWphysicsumanitobacaiup ap SEARCH ENGINES Here are several good search engines that Will also lead you to many interesting sites much comes up All The Web Alta Vista Excite Google HotBot Lycos Northern Lights OpenText Index Yahoo Dej aNeWS NeWSGroup Archives Surf by entering the keyword radiometry and see how WWWallthewebcom WWW altavistacom WWWexcitecom WWWgooglecom WWWhotbotcom WWWlycoscom WWWnorthernlightcom WWWopentextcom WWWyahoocom WWWdej aneWScom 61 APPENDIX X RADIOMETRY 8t PHOTOMETRY BIBLIOGRAPHY In 1969 Fred Nicodemus authored a paper Optical Resource Letter on Radiometry J OSA 59243 It was reprinted in an AIP Radiometry reprint collection in 1981 This bibliography is intended to update and supplement the 1969 version The topic breakdown is more in line With the order of topics in this book than the original Individual papers are for the most part bypassed in favor of books significant book chapters monographs or reprint collections SYMBOLS UNITS and TERMINOLOGY American National Standard Nomenclature and Definitions for Illuminating Engineering ANSI Standard ANSIIESNA RP16 96 1996 CIE International Lighting Vocabularv CIE Publ 17 1970 ISO Quantities and units Part 6 Light and related electromagnetic radiations ISO Standards Handbook Quantities and Units 38915 1993 Symbols Units and Nomenclature in Physics International Union of Pure and Applied Physics 1987 Wyatt CL V Privalsky and RT Datlu Recommended Practice Svmbols Units and Uncertaintv Analvsis for Radiometric Sensor Calibration NIST Handbook 152 1998 GENERAL Boyd RW Radiometrv and the Detection of Optical Radiation Wiley 1983 Good for the theoretical aspects of radiation geometry along With several other topics Bramson MA Infrared A Handbook for Applications Plenum 1966 Grum EC and RJ Becherer Optical Radiation Measurements I Radiometrv Academic 1979 The best allaround book on radiometry to date Hadni A Essentials of Modern thsics Applied to the Studv of the Infrared Pergamon 1967 Holter MR S Nudelman GH Suits WL Wolfe and GJ Zissis Fundamentals of Infrared Technology Macmillan 1962 Jamieson JA RH McFee GN Plass RH Grube and RG Richards Infrared Physics and Engineering McGraWHill 1963 Kruse PW LD McGlaughlin and RB McQuistan Elements of Infrared Technology Wiley 1962 McCluney WR Introduction m Radiometry and Photometry Artech House 1994 A recent entry again slightly slanted to the authors specialty of solar energy applications Both elementary and thorough Spiro IJ and M Schlessinger Infrared Technology Fundamentals Dekker 1989 Wolfe WL and G Zissis The Infrared Handbook Office of Naval Research Washington DC 1978 The most bang for your buck At 60 everybody should have one Available from SPIE Wolfe WL Introduction to Radiometry SPIE Bellingham WA 1998 Uneven and terse in spots still recommended He was my mentor Zalewski EF Radiometry and Photometry Chapter 24 in Handbook of Optics Vol II McGrawHill 1995 An excellent review GEOMETRIC RADIATION TRANSFER Gershun A The Light Field trans P Moon MIT Press 1939 Hottel HC amp AF Sarofim Radiative Transfer McGrawHill 1967 Howell JR A Catalog of Radiation Configuration Factors McGrawHill 1982 The current edition can be found online at sage meutexasedu Nhowell Nicodemus FE etal SelfStudv Manual on Optical Radiation Measurements NBS Technical Note 910XX National Institute of Standards and Technology Washington DC various dates A series that is rather theoretical with increasing coverage Some may be out of print Check GPO for availability Siegel R and JR Howell Thermal Radiation Transfer Hemisphere 1981 Intended for mechanical and heat transfer engineers uses nonSI units like BTU39s degrees Rankine and the wrong intensity and highly detailed this book is the best compendium on radiative transfer Sparrow EM amp RD Cess Radiation Heat Transfer BrooksCole 1970 Taylor JH Radiation Exchange Academic 1990 RADIOSITY AND RAY TRACING Ashdown I Radiositv A Programmer s Perspective Wiley 1994 Cohen MF and JR Wallace Radiositv and Realistic Image Svntheses Academic 1993 OPTICAL RADIATION SOURCES Carlson EE and CN Clark Light Sources for Optical Devices Chap 2 in Applied Optics and Optical Engineering Vol 1 R Kingslake ed Academic 1975 Coulson KL Solar and Terrestrial Radiation Academic 1975 Eby J E amp RE Levin Incoherent Light Sources Chap 1 in Applied Optics and Optical Engineering Vol 7 R R Shannon and J Wyant eds Academic 1975 Green AS ed The Middle Ultraviolet Its Science and Technology Wiley 1966 Grum F amp RJ Becherer Radiometry Vol 1 in Optical Radiation Measurements Academic 1979 Chap 5 Hewitt H amp AS Vause Lamps and Lighting Elsevier 1966 Iqbal M An Introduction to Solar Radiation Academic 1983 Jacobs PA Thermal Infrared Characterization of Ground Targets and Backgrounds SPIE TT26 1996 Kryskowski D amp GH Suits Natural Sources Chap 3 in Sources of Radiation GJ Zissis ed Vol 1 of The Infrared amp ElectroOptical Handbook SPIE Press 1993 LaRocca AJ Arti cial Sources Chap 2 in Sources of Radiation GJ Zissis ed Vol 1 of The Infrared amp ElectroOptical Handbook SPIE Press 1993 LaRocca AJ Arti cial Sources Chap 10 in Handbook of Optics Vol 1 Part 4 Optical Sources McGraW Hill 1995 Luckiesh M Applications of Germicidal Erythemal and Infrared Energy Van Nostrand 1946 Malacara H Z amp A Morales R Light Sources Chapter 5 In Geometrical and Instrumental Optics Academic 1988 Moon P The Scientific Basis of Illuminating Engineering McGraWHill 1936 reprinted by Dover 1961 Murdoch J B Illumination Engineering From Edison s Lamp to the Laser Macmillan 1985 RCA ElectroOptics Handbook RCA Lancaster PA 1974 Now available from Burle Rea M ed Lighting Handbook Reference and Application 8th edition Illuminating Engineering Society of North America 1993 Richmond J C amp FE Nicodemus Blackbodies BlackbodV Radiation and Temperature Scales NBS SelfStudy Manual on Optical Radiation Measurements Part 1 Chapter 12 GPO 1985 Silfvast WT quotLasersquot Chap 11 in Handbook of Optics Vol 1 Part 4 Optical Sources McGraw Hill 1995 Suits GH Natural Sources Chapter 3 in The Infrared Handbook ERIM 1982 Distributed By SPIE Weissman RH quotLight Emitting Diodesquot Chap 12 in Handbook of Optics Vol 1 Part 4 Optical Sources McGraw Hill 1995 Zissis GJ amp AJ Larocca Optical Radiators and Sources in Handbook Of Optics Chapter 3 McGrawHill 1978 DETECTORS Ambroziak A Semiconductor Photoelectric Devices Gordon amp Breach 1969 Barbe DE ed Chargecoupled DeVices SpringerVerlag 1980 Bartelson CJ amp EC Grum Optical Radiation Measurements V Visual Measurements Academic 1984 Beynon JDE amp DR Lamb Chargecoupled DeVices and their Applications McGrawHill 1980 Biberman L amp S Nudelman Photoelectronic Imaging DeVices Plenum 1970 Two volumes Boynton RM Human Color Vision Holt Rinehart amp Winston 1979 Budde W Optical Radiation Measurements IV Pthical Detectors of Optical Radiation Academic 1983 The best practical book on detectors and their characterization slanted a bit towards the Visible spectrum Buil C CCD Astronomy WillmanBell 1991 Chappell A ODtoelectronics TheorV and Practice McGrawHill 1978 Csorba IP Image Tubes Howard W Sams 1985 Dennis PNJ Photodetectors Plenum 1986 Dereniak EL amp G Boreman Infrared Detectors and Systems Wiley 1996 Dereniak EL amp D Crowe Optical Radiation Detectors Wiley 1984 Good general book slanted towards the infrared Donati S Photodetectors Devices Circuits and Applications Prentice Hall 2000 A new entry concise accurate highly recommended Eccles MJ ME Sim amp KP Tritton Low Light Level Detectors in Astronomy Cambridge 1983 Engstrom RW RCA Photomultiplier Handbook RCA 1980 Available from Burle Holst GC CCD Arravs Cameras and Displavs SPIE 1996 Hudson RD and JW Hudson eds Infrared Detectors Hutchinson and Ross 1975 A collection of the more important papers to date Janesick JR Scientific Chargecoupled Devices SPIE 2001 Keyes RJ ed Optical and Infrared Detectors SpringerVerlag 1980 McLean IS Electronic Imaging in Astronomy Wiley 1997 Photomultiplier Tube Principle to Application Hamamatsu Photonics 1994 Photomultiplier Tubes Principles and Applications Philips Photonics 1994 Rieke GH Detection of Light from the Ultraviolet to the Submillimeter Cambridge 1994 Rose A Vision Human and Electronic Plenum 1973 Ross M Laser Receivers Wiley 1966 Sequin CH amp MF Tomsett Charge Transfer Devices Academic 1975 Smith RA FE Jones amp RP Chasmar The Detection and Measurement of Infra red Radiation Oxford 1957 Sommer AH Photoemissive Materials Wiley 1968 Reprinted by Krieger 1980 Vincent J D Fundamentals of Infrared Detector Operation and Testing Wiley 1990 Separate chapters on cryogenics vacuum systems and detector electronics Answers many of those nagging questions Highly recommended Young AT Photomultipliers their causes and cures Chapter 1 in Methods of Experimental thsics Astrophvsics N Carleton ed Vol 12 Academic 1974 The major handbooks offer one or more chapters dealing with optical radiation detectors These include the following Accetta J S amp DL Shumaker eds Infrared and ElectroOptical Svstems Handbook SPIE 1993 See Vol 3 Chapter 4 Bass M ed Handbook of Optics Vol 1 McGraWHill 1995 Parts 5 6 and 7 contains chapters 15 thru 25 all pertinent to detectors and detection Driscoll WG amp W Vaughn Handbook of Optics McGraWHill 1978 Chap 4 Wolfe WL ed Handbook of Militarv Infrared Technologv ONR Washington 1965 Chapters 11 amp 12 Wolfe WL amp Zissis G eds The Infrared Handbook ERIM and SPIE 1978 Chapters 1116 Several books in the series Semiconductors and Semimetals ed RK Willardson amp AC Beer are relevant Vols 5 and 12 both treat infrared detectors and Vol 11 deals exclusively With solar cells Vol 47 deals With Uncooled Infrared Imaging Array Systems Similarly the series Advances in Electronics and Electron Physics is rich in pertinent articles Numerous volumes deal With imaging detector conference proceedings While other have significant feature articles Most notable are volumes 34 and 55 Another rich source for detector information and probably the best for assessment of the current stateofart are the Proceedings of the various conferences of the SPIE The International Optical Engineering Society They have several major conventions per year each having one or more conferences on detectors Compilations of the best proceedings papers along With seminal papers are often gathered in their Milestones series Several detector manufacturers publish manuals collections of applications notes etc Particularly attractive are the photomultiplier tube books by Burle formerly RCA Hamamatsu and Philips and the CCD books by EGampG Reticon and Fairchild Data books by Dalsa EGampG Vactec Texas Instruments Thompson CSF etc are also quite helpful NOISE ELECTRONICS AND SIGNAL PROCESSING Bell DA Noise and the Solid State Wiley 985 Davies ER Electronics Noise and Signal RecoverV Academic 1983 Fish PJ Electronic Noise and Low Noise Design McGraWHill 1994 Frederiksen TM Intuitive IC Op Amps National Semiconductor 1984 Graeme JG Photodiode Amplifiers ODAmp Solutions McGraWHill 1996 Gupta MS ed Electrical Noise Fundamentals and Sources IEEE 1977 Horowitz P amp W Hill The Art of Electronics Cambridge 1989 The best single book available for the broad field of electronics my personal favorite Jung WG IC Opamp Cookbook Howard Sams 1980 More tutorial than Stout with fewer useful circuits Motchenbacher CD and J A Connelly LowNoise Electronic Svstem Design Wiley 1993 Ott HW Noise Reduction Techniques in Electronic Svstems 2nd ed Wiley 1988 Pease RA Troubleshooting Analog Circuits ButterworthHeinemann 1991 Stout DF amp M Kaufman Handbook of Operational Amplifier Circuit Design McGrawHill 1976 Excellent singlepurpose reference book Van der Ziel A Noise in Measurements Wiley 1976 Vergers CA Handbook of Electrical Noise Measurement and Technology TAB 1979 Williams J Analog Circuit Design Art Science and Personalities Butterworth Heinemann 1991 Williams J The Art and Science of Analog Circuit Design Butterworth Heinemann 1995 Wilmshurst TH Signal Recovery Adam Hilger 1990 Yariv A Optical Electronics in Modern Communications Oxford 1997 Chapter 10 treats noise in optical detection and generation RAD IOMETRI C INSTRUMENTS Begunov BN NPZakaznov SI Kiryushinand VI Kuzichev Optical Instrumentation Theorv and Design MIR 1988 Hudson RD Infrared System Engineering Wiley 1969 Dated but still valuable James JF and RS Sternberg Design of Optical Spectrometers Chapman amp Hall 1969 Seyrafi K ed Engineering Design Handbook on Infrared Militarv Svstems United States Army Materiel Command Pamphlet AMCP 706127 1971 Similar to Hudson but in MILformat Later modified and self published as ElectraOptical Systems Analysis ElectroOptical Research Co Los Angeles 1985 Wolfe WL Introduction to Infrared Svstem Design SPIE TT24 SPIE 1996 Wolfe WL Introduction to Imaging Spectrometers SPIE TT25 SPIE 1997 Wolfe WL Infrared Design Examples SPIE TT36 SPIE 1999 Wyatt CL Radiometric Systems Design Macmillan 1987 More for the designer than the calibrator but very useful Later available as ElectroOptical System Design for Information Processing McGraWHill 1990 More for the system designer but very useful RADIOMETRIC MEASUREMENTS ERRORS Baird DC Experimentation An Introduction to Measurement Theorv and Experiment Design PrenticeHall 1962 Beers Y Introduction to the Theorv of Error AddisonWesley 1957 Bevington PR amp DK Robinson Data Reduction and Error Analysis for the Physical Sciences 2nd ed McGraWHill 1992 Calibration Philosophv ip Practice 2nd ed Fluke Corporation1994 Available directly from them Holman JP Experimental Methods for Engineers McGraWHill 1978 Mandel J The Statistical Analysis of Experimental Data Dover 1984 Meyer SL Data Analeis for Scientists and Engineers Wiley 1975 Rabinovich S Measurement Errors Theorv and Practice AIP Press 1995 Taylor BN amp CE Kuyatt Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results NIST Technical Note 1297 1994 Available on the W W W Taylor JR An Introduction to Error Analvsis 2nd ed University Science 1997 Young HD Statistical Treatment of Experimental Data McGraWHill 1962 MEASUREMENT OF RADIOMETRIC QUANTITIES Bauer G Measurement of Optical Radiations Focal Press 1965 Forsythe WE ed Measurement of Radiant Energv McGraWHill 1937 Kostkowski HJ Reliable Spectroradiometry Spectroradiometry Consulting PO 2747 La Plata MD 20646 Selfpublished lessons learned over some 40 years Authoritative Malacara D thsical Optics and Light Measurements Academic 1988 Chap 6 A69 PHOTOMETRY Barrows WE Light Photometrv and Illuminating Engineering McGrawHill 195 1 Bouguer P Essai d optique sur la gradation de la lumiere Paris 1729 It all started here Translated into English by Middleton The Gradation of Light Toronto 1961 DeCusatis C Handbook of Applied Photometrv AIP Press 1997 Authoritative with pertinent chapters written by technical experts at BIPM CIE and NIST Primarily for visible radiation mostly excellent Skip chapter 4 Fabry C Photometrie Revue d Optique Paris 1927 Keitz HAE Light Calculations and Measurements Cleaver Hume 1955 MacMillan 1971 Lambert J H Photometrie Augsberg 1760 A beautiful English translation from the original Latin with copious notes by David DiLaura was published in 2001 available from IESNA Ohno Y Radiometrv and Photometrv Review for Vision Optics Chapter 14 in Handbook of Optics III McGrawHill 2001 Palmer J M Radiometrv and Photometrv Units and Conversions Chapter 7 in Handbook of Optics III McGrawHill 2001 Stimson A Photometrv and Radiometrv for Engineers Wiley 1974 Walsh JWT Photometry 3rd ed Constable 1958 reprinted by Dover 1965 The standard reference since 1924 ASTRONOMICAL MEASUREMENT OF LIGHT I choose not to include these in photometry to avoid confusion with the strict definition of the word the measurement of light Henden AA amp RH Kaitchuk Astronomical Photometry Van Nostrand Reinhold 1982 Hopkins J L Zen and the Art of Photoelectric Photometrv HPO Desktop Publishing 1990 COLOR and APPEARANCE BergerSchunn A Practical Color Measurement Wiley 1994 Billmeyer EW and M Salzman Principles of Color Technology Wiley Interscience 1981 Burnham RW RM Hanes amp CJ Bartleson Color a guide to the basic facts and concepts Wiley 1963 Chamberlin CJ amp DG Chamberlin Colour Its Measurement Computation and Application Heyden 1980 Committee on Colorimetry The Science of Color Optical Society of America Crowell 1953 A second edition is due any day now Evans RM An Introduction to Color Wiley 1948 Fortner B amp TE Meyer Number by Colors Springer 1997 Grum EC and CJ Bartelson Optical Radiation Measurements II Color Measurement Academic 1981 Hardy AC Handbook of Colorimetry MIT Press 1936 Hunter R S The Measurement of Appearance Wiley 1987 Kortum G Kolorimetrie Photometrie und Spektrometrie SpringerVerlag 1962 Judd DB Contributions to Color Science ed DL MacAdam NBS Special Publication SP545 1979 A collection of the significant papers by Judd the Deane of colorimetry Judd DB and G Wysczecki Color in Business Science and Industrv Wiley 1975 Wright WD The Measurement of Colour Macmillan 1969 Wyszecki G and WS Stiles Color Science 1st ed Wiley 1967 2nd revised ed Wiley 1982 This classic has been reprinted in a lowcost paperback format by Wiley 2000 A must RADIOMETRIC PROPERTIES OF MATERIALS Blau HH and H Fischer Radiative Transfer from Solid Materials Macmillan 1962 Burgess C and K D MielenZ Advances in Standards and Methodologv in Spectrophotometry Elsevier 1987 Clauss FJ Material Effects in Spacecraft Thermal Control Wiley 1960 Gubareff GG JE Janssen amp RH Torberg Thermal Radiation Properties Survev Honeywell 1960 Hapke B Theorv of Re ectance and Emittance Spectroscopv Cambridge 1993 Kamler J Luminescent Screens Photometry and ColorimetrV lllife 1969 Katzoff S ed Symposium on Thermal Radiation of Solids NASA SP55 1965 Kyle TG Atmospheric Transmission Emission and Scattering Pergamon 1991 Layin EP Specular Re ection Elseyier 1971 Mayrodinuenu R J 1 Schultz and O Menis Accuracy in Spectrophotometry and Luminescence Measurements NBS Special Publication 378 1973 Mielenz KD ed Optical Radiation Measurements HI Measurement of Photoluminescence Academic 1982 Richmond J C ed Measurement of Thermal Radiation Properties of Solids NASA SP31 1963 Schenk GH Abs01quotption of Light and Ultraviolet Radiation Fluorescence and Phosphorescence Emission Allyn amp Bacon 1973 St0yer JC Optical Scattering Measurement and Analysis SPIE 1995 Tilley R Colour and the Optical Properties of Materials Wiley 2000 SPECTROSCOPY Barnes RB RC Gore U Liddel amp VZ Williams Infrared Spectroscopy Industrial Applications and Bibliography Reinhold 1944 Brode WR Chemical Spectroscopy Wiley 1943 Edisbury J R Practical Hints on Absorption Spectrometry Plenum 1967 Harrick NJ lnternal Re ection Spectroscopy Harrick Scientific 1967 Harrison GR RC Lord amp JR Loofbourow Practical Spectroscopy PrenticeHall 1948 James JF amp RS Sternburg The Design of Optical Spectrometers Chapman amp Hall 1969 Kortum G Re ectance Spectroscopy SpringerVerlag 1969 Lakowicz JR Principles of Fluorescence Spectroscopy Plenum 1983 Lothian GF Absorption Spectrophotometry Hilger amp Watts 1958 Meehan EJ Optical Methods of Analysis lnterscience 1964 Sawyer RA Experimental Spectroscopy PrenticeHall 1951 Stearns El The Practice of Absorption Spectrophotometry Wiley 1969 A72 Stewart JE Infrared Spectroscopy Marcel Dekker 1970 Wendlandt WW amp HG Hecht Reflectance Spectroscopy Interscience 1966 Workman J and A Springsteen Applied Spectroscopy A Compact Reference for Practitioners Academic 1998 LASER POWER amp ENERGY Heard HG Laser Parameter Measurements Handbook Wiley 1968 TEMPERATURE DeWitt DP and GD Nutter Theory and Practice of Radiation Thermometry Wiley 1988 Kaplan H Practical Applications of Infrared Thermal Sensing andf Imaging Eguipment SPIE TT34 SPIE 1999 Lloyd JM Thermal Imaging Systems Plenum 1975 Quinn T Temperature 2nd ed Academic 1990 Richmond JC and DP Dewitt eds Applications of Radiation Thermometrv ASTM 1985 Wood WP and JM Cork Pyrometry McGrawHill 1941 RADIOMETRIC STANDARDS AND CALIBRATION Hengtsberger F Absolute Radiometry Academic 1989 Broad coverage with emphasis on roomtemperature electricallycalibrated thermal radiometers Wyatt CL Radiometric Calibration Theory and Methods Academic 1978 Good fairly thorough treatment somewhat slanted towards the authors specialty which is farinfrared cryogenic radiometry COMPILATIONS Drummond AJ ed Precision Radiometry Vol 14 Advances in Geophysics Academic 1970 Hammond III HK and HL Mason Selected NBS Papers on Radiometrv and Photometry in Precision Measurement and Calibration NBS Special Publication 300 Vol 7 1971 Johnson RB and WL Wolfe Selected Papers on Infrared Design 2 vols SPIE 1985 Nimeroff I Selected NBS Papers on Colorimetrv in Precision Measurement and Calibration NBS Special Publication 300 Vol 9 1972 Spiro IJ ed Selected Papers on Radiometry SPIE Milestone MS14 SPIE 1990 OPTICAL DESIGN Fischer RE amp B TadicGaleb Optical System Desigp McGrawHill 2000 Kingslake R Lens Design Fundamentals Academic 1978 Kingslake R Optical System Desigp Academic 1983 Mouroulis P amp J Macdonald Geometrical Optics and Optical Design Oxford 1997 O Shea DC Elements of Modern Optical Design Wiley 1985 Shannon RR The Art and Science of Optical Design Cambridge 1997 Bob was my professor for optical design Smith GH Practical ComputerAided Lens Design WillmannBell 1998 Smith WJ Modern Optical Engineering 3rd ed McGrawHill 2000 MISCELLANEOUS Hobbs PCD Building ElectroOptical Systems Making It All Work Wiley 2000 Except for his flippant and indefensible attitude towards radiometry and those who practice the art this recent publication is a pretty useful book Poynton CA A Technical Introduction to Digital Video Wiley 1996 TECHNICAL ORGANIZATIONS IN RADIOMETRY amp PHOTOMETRY CIE The Commission Internationale Q L39Eclairage CIE has numerous Technical Committee Reports that are relevant Write to Thomas Lemons TLA Lighting Consultants Inc 7 Pond St Salem MA 01970 or call 508 7456870 FAX 508 7414420 for a listing of current publications and pricing Check into their web page for more information Some pertinent reports primarily from DiVision 2 are listed in Appendix VIII CORM The Council for Optical Radiation Measurements CORM was founded over twenty years ago to promote optical radiation measurement science and engineering and foster cooperation among the many government agencies industrial firms and universities and to formulate and transmit national needs to NIST They meet annually in May and publish Optical Radiation News Optical biannually Contact CORM Treasurer 1043 Grand Ave 312 St Paul MN 55105 wwwcormorg CORM documents are listed in Appendix Vlll NEWRAD The NEWRAD conference series is an outgrowth of a meeting organized by Peter Foukal and held in Cambridge MA in 1985 The proceedings of the first meeting were a private publication The second meeting took place at NFL in London in 1988 and the proceedings were published as New Developments and Applications in Radiometry N Fox and D Nettleton eds by 1013 Publishing London 1989 The proceedings of the next four meetings held in Davos 1990 Baltimore 1992 Berlin 1995 and Tucson 1997 The proceedings of these meetings were published as special issues of Metrologia Elsevier Volumes 283 304 326 and 354 respectively The seventh conference was held October 2527 1999 in Madrid Check out httpnewradmetrologiacsices NIST The US National Institute of Science and Technology NIST formerly National Bureau of Standards NBS has a number of valuable special publications that describe their calibration services and procedures Appropriate ones include the following They may be purchased from NTlS NBS Measurement Services Spectral Radiance Calibrations J H Walker R D Saunders and A T Hattenburg Natl Bur Stand US Spec Publ 2501 1987 NBS Measurement Services Far Ultraviolet Detector Standards L R Canfield and N Swanson Natl Bur Stand US Spec Publ 2502 1987 NBS Measurement Services Radiometric Standards in the Vacuum Ultraviolet J Z Klose J M Bridges and W R Ott Natl Bur Stand US Spec Publ 2503 1987 NBS Measurement Services Regular Spectral Transmittance K L Eckerle J J Hsia K D MielenZ and V R Weidner Natl Bur Stand US Spec Publ 2506 1987 NIST Measurement Services Spectral Re ectance P Y Barnes E A Early and A C Parr Natl Inst Stand Technol Spec Publ 2508 1987 revised 1997 The NBS Photodetector Spectral Response Calibration Transfer Program EF Zalewski Natl Bur Stand US Spec Publ 25017 45 1988 NlST Measurement Services Photometric Calibrations Y Ohno Natl Inst Stand Technol Spec Publ 25037 1997 NlST Measurement Services Radiance Temperature Calibrations Natl Inst Stand Technol Spec Publ 25043 1997 NBS Measurement Services Spectral lrradiance Calibrations J H Walker R D Saunders J K Jackson and D A McSparron Natl Bur Stand US Spec Publ 25020 1987 NlST Measurement Services Spectroradiometric Detector Measurements Parts 1 and H Ultraviolet and Visible to Near Infrared Detectors T C Larason S S Bruce and A C Parr Natl Inst Stand Technol US Spec Publ 25041 1998 NlST Measurement Services Spectroradiometric Detector Measurements Part 111 Infrared Detectors A L Migdall and G Eppeldauer Natl Inst Stand Technol US Spec Publ 25042 1998 SPIE Proceedings of the SP1E are published unrefereed papers as presented at conferences of SPIE The International Society for Optical Engineering Several conferences and resulting proceedings have been devoted to radiometry and photometry They are 196 Measurements of Optical Radiations 1979 499 Optical Radiation Measurements l 1984 888 Laser Beam Radiometry 1988 1109 Optical Radiation Measurements 11 1989 2161 Photometry 1993 2815 Optical Radiation Measurements Ill 1996 OPEN LITERATURE Numerous archival and trade journals also offer significant papers on radiometry and detection of optical radiation They include Applied Optics OSA IEEE Transactions on Electron Devices Infrared Physics and Technology Elsevier Journal of the Optical Society of America A OSA Journal of Scientific Instruments Laser Focus World free Lightwave Technology IEEE Optical Engineering SPIE Photonics Spectra free Review of Scientific Instruments PUBLICATIONS AVAILABLE ON THE WORLD WIDE WEB All you ever wanted to know about the SI is contained at BIPM wwwbipmfr and at NIST physicsnistgovcuu Available publications highly recommended include The International System of Units SI 7th edition 1998 direct from BIPM The official document is in French the English translation is available in PDF format NIST Special Publication SP330 The International System of Units SI The US edition of the above BIPM publication Available in PDF format NIST Special Publication SP811 Guide for the Use of the International System of Units SI Available in PDF format Papers published in NIST Journal of Research since 1995 are also available on the web in PDF format APPENDIX XI SELECTED VENDORS OF RADIOMETRIC EQUIPMENT NOTICE Items of commercial equipment identified in this section are part of a survey of the field of available equipment This identification does not imply endorsement by the author or the University of Arizona nor does it imply that the identified equipment is the best available for the purpose This list is by its very nature both incomplete and at the same time obsolete See buyers39 guides from Lasers and Optronics Laser Focus World Photonics Spectra Physics Today and Spectroscopy for more uptodate listings BLACKBODY RADIATION SOURCES CI Systems ElectroOptical Industries Eppley Laboratory OTHER CALIBRATION SOURCES Eppley Laboratory Gamma Scientific Hoffman Engineering Corp Labsphere LIGHT SOURCES LUMINESCENT American Ultraviolet Cathodeon deuterium Hamamatsu Hanovia ILC Technology LIGHT SOURCES THERMAL Buck Scientific DBA Systems Gilway Technical Lamp 79 Graesby Infrared Mikron Instrument Santa Barbara Infrared LI COR Optronic Laboratories Oriel Instruments ORC Lighting Products Oriel Instruments OsramSylvania Xenon Corp Oriel Instruments WelshAllen DETECTORS PHOTOCONDUCTIVE EGampG Vactec CdS CdSe OptoElectronics PbS PbSe Fermionics HngTe DETECTORS PHOTODIODE Advanced PhotoniX EpitaXX InGaAs Centronic Fermionics InGaAs HngTe Cincinnati Electronics InSb Hamamatsu EGampG Judson Ge InSb International Radiation Detectors EGampG Optoelectronics Silicon Sensors EGampG Vactec UDT Sensors Si DETECTORS PHOTOMULTIPLIER Burle Philips EMR Photoelectric Thorn EMI Hamamatsu DETECTORS THERMAL Amber bolometers CalSensors pyroelectric thermopiles Dexter Research Center thermopiles EDO Barnes bolometers pyroelectric thermopiles EGampG Heimann pyroelectric thermopiles Eltec Instruments pyroelectric Eppley Laboratories thermopiles Infrared Laboratories bolometers Laser Probe pyroelectric Meggett Avionics thin film thermopiles Midwest Research Technologies bolometers Molectron Detector pyroelectric Sensor Physics thermopiles Spiricon pyroelectric DETECTOR ARRAYS Amber Loral Fairchild CID Technologies Mitsubishi Cincinnatti Electronics Philips Photonics Dalsa Rockwell ElectroOptical Center Eastman Kodak Scientific Imaging Technologies SITe EEV Ltd Texas Instruments EGampG Reticon Thompson Components amp Tubes Hamamatsu Toshiba GENERAL PURPOSE RADIOMETERS EGampG Gamma Scientific ElectroOptical Industries infrared Graesby Optronics general purpose and absolute QED International Light Labsphere Laser Probe pyroelectric and ECR Optronic Laboratories Wide range LASER POWER AND ENERGY METERS Coherent Instruments Newport CorpOphir Optronics DigiRad Scientech calorimetric ILX Lightwave Spawr Optical Research high power Laser Probe pyroelectric Spiricon pyroelectric arrays Molectron pyroelectric FIBER OPTIC RADIOMETERS Anritsu ILX Lightwave EXFO Photodyne Fotec Thorlabs PHOTOMETERS Gamma Scientific LMT Lichtmesstechnik Hoffman Engineering Photo Research International Light SPECIALIZED METERS AND INSTRUMENTS Biospherical Instruments underwater Cambridge Research amp Instrumentation cryogenic absolute ECR Eppley Laboratories solar radiation instrumentation Exotech portable enVironmental studies LICOR quantum underwater solar Oxford Instruments cryogenic absolute ECR Spectronics ultraViolet Stanford Research Systems photon counter LIA MISCELLANEOUS RADIOMETRIC ACCESSORIES Eastman Kodak IR detection cards BaSO4 reflectance Standard Hoffman Engineering integrating spheres Labsphere transmission and re ection diffusers integrating spheres MEASUREMENT AND CALIBRATION LABORATORIES National Institute of Standards and Technology USA National ResearchCouncil Canada Optical Test amp Calibration Ltd OptoCal MONOCHROMATORS Acton Research Bentham Instruments CVI Laser Instruments SA McPherson Optronic Laboratories SPECTROPHOTOMETERS Acton Research Beckman Instruments Bomem Hartmann amp Braun FTIR Bruker Instruments Buck Scientific Edinburgh Instruments Hitachi Instruments Mattson Instruments FTIR SPECTRORAD IOMETERS Analytical Spectral Devices Bentham Instruments Oriel Corp Photon Technology International Research Support Instruments Scientific Measurement Systems Spectral Energy SPEX Industries Milton Roy Nicolet Instruments FTIR PerkinElmer Shimadzu Corporation Spectral Instruments Thermo J arrellAsh Varian Associates Cary Biospherical Instruments underwater Control Development EDO Barnes Engineering multispectral filter Gamma Scientific general purpose Geophysical amp EnVironmental Research LiCor portable underwater Ocean Optics miniature fiber optic Optronic Laboratories Wideband high precision Oriel Instruments Spectron diode array portable SPECTROREFLECTOMETERS AZ Technology Labsphere Optronic Laboratories 82 RADIATION THERMOMETERS Anritsu Capintec Everest Interscience Ircon Land Instruments Linear Laboratories THERMAL IMAGING SYSTEMS AGEMA Infrared Systems Amber FLIR Systems Mikron Instrument Omega Engineering Pyrometer Instrument Co Raytek Wahl Instruments Williamson Corp Inframetrics Mitsubishi COLOR AND APPEARANCE INSTRUMENTS HunterLab Macbeth Minolta last update 132000 jmp Photo Research XRite 83 APPENDIX XII RADIOMETRY PROGRAMS AND DATA ON THE CD Introduction to radiometry SUN Propagation of optical radiation sevezal configuration factors Foote s law including cosA Radiometric properties ofmaterials Transmission reflection absorption Relationship between transmission reflection and absorption specular materials Diffusing materials Generation of optical radiation EElQQZC EXE and spreadsheet watts amp photons tungsten emissiVity along With other materials directional emittance from specular surfaces uorescentlamp spectra re ectances artificial amp natural sunlight AMO1235 LOWTRANcurves 2 meter lab 1 km sevexal condx horiz Vexhcal phosphors gloliar xenon amp mercury arcs cuxve tting for tungsten lamps Detection of optical radiation photopic and scotopic cuxVes spectral response of film spectral response amp D ofdetectors absorption coeffof si Radiometric Instruments mirror reflectances select filter transmissions absorption amp interference vs angle transmission amp reflection diffusers spectral amp angular Whites blacks opamp characteristics noise bandwidth chopping factors cold stop improvement snr vs lowpass sig avg demo LIA demo Radiometric Measurements measurement equations Range equations normalization bW amp fov photometry colorimetry tristimulus curves action spectra UVA UVB UVC PhAR etc Correlated color temp Distribution temp Diffraction calculation Radiometric Calibration Standard calibration wavelengths representative FEL curve transmittance amp didymium transmission curves Halon amp BaSO4 reflectance Au and Al standard spectral reflectances Kodak gray card reflectance Order Code RL30319 CRS Report for Congress Presidential Claims of Executive Privilege History Law Practice and Recent Developments Updated August 21 2008 Morton Rosenberg Specialist in American Public Law American Law Division Prepared for Members and Committees of Congress Congressional Research Service Presidential Claims of Executive Privilege History Law Practice and Recent Developments Summary Presidential claims of a right to preserve the con dentiality of information and documents in the face of legislative demands have gured prominently though intermittently in executivecongressional relations since at least 1792 Few such interbranch disputes over access to information have reached the courts for substantive resolution the vast majority achieving resolution through political negotiation and accommodation In fact it was not until the Watergaterelated lawsuits in the 1970 s seeking access to President Nixon s tapes that the existence of a presidential con dentiality privilege was judicially established as a necessary derivative of the President s status in our constitutional scheme of separated powers Of the nine court decisions involving interbranch or private information access disputes four have involved Congress and the Executive Two of these resulted in decisions on the merits The Nixon and postWatergate cases established the broad contours of the presidential communications privilege Under those precedents the privilege which is constitutionally rooted could be invoked by the President when askedto produce documents or other materials or information that re ect presidential decisionmaking and deliberations that he believes should remain confidential Ifthe President does so the materials become presumptively privileged The privilege however is quali ed not absolute and can be overcome by an adequate showing of need Finally while reviewing courts have expressedreluctance to balance executive privilege claims against a congressional demand for information they have acknowledged they will do so if the political branches have tried in good faith but failed to reach an accommodation However until the District of Columbia Circuit s 1997 ruling in In re Sealed Case Espy and 2004 decision in Judicial Watch v Department of Justice these judicial decisions had left important gaps in the law of presidential privilege Among the more signi cant issues left open included whether the President has to have actually seen or been familiar with the disputed matter whether the presidential privilege encompasses documents and information developed by or in the possession of officers and employees in the departments and agencies of the Executive Branch whether the privilege encompasses all communications with respect to which the President may be interested or is it con ned to presidential decisionmaking and if so is it limited to any particular type of presidential decisionmaking and precisely what kind of demonstration of need must be shown to justify release of materials that qualify for the privilege The unanimous panel in Espy and the subsequent reaffirmation of the principles articulated in Espy byJualicial Watch authoritatively addressed each of these issues in a manner that may have drastically alteredthe future legal playing eld in resolving such disputes A more recent dispute with Congress involving the removal and replacement of nine United States Attorneys has drawn formal claims of privilege by President George W Bush Those privilege claims have been challenged in a civil suit brought by the House Judiciary Committee seeking declaratory and injunctive relief with respect to refusals to appear to testify and to provide documents by two subpoenaed present and former officials A recent district court ruling upholding the committee s challenge may serve to further amplify the law in this area Contents Introduction l The Watergate Cases 3 PostWatergate Cases 7 Executive Branch Positions on the Scope of Executive Privilege Reagan Through George W Bush 10 Implications and Potential Impact of the Espy and Judicial Watch Rulings for Future Executive Privilege Disputes 17 Recent Developments George W Bush Claims of Executive Privilege 24 Concluding Observations 34 Appendix 37 Presidential Claims of Executive Privilege From the Kennedy Administration Through the George W Bush Administration 37 1 Kennedy 37 2 Johnson 37 3 Nixon 37 4 Ford and Carter 37 5 Reagan 38 6 Bush George H W 38 7 Clinton 38 8 Bush George W 39 Presidential Claims of Executive Privilege History Law Practice and Recent Developments Introduction Presidential claims of a right to preserve the con dentiality of information and documents in the face of legislative demands have gured prominently though intermittently in executivecongressional relations since at least 1792 when President Washington discussed with his cabinet how to respond to a congressional inquiry into the military debacle that befell General St Clair s expedition1 Few such interbranch disputes over access to information have reached the courts for substantive resolution the vast majority achieving resolution through political negotiation and accommodation2 In fact it was not until the Watergaterelated lawsuits in the 1970 s seeking access to President Nixon s tapes that the existence of a presidential confidentiality privilege was judicially established as a necessary derivative of the President s status in the US constitutional scheme of separated powers Of the nine court decisions involving interbranch or private information access disputes3 four have involved Congress and the Executive4 Two of these resulted in decisions on the merits5 One other case involving legislation granting custody of President Nixon s presidential records to the Administrator of the General Services Administration also determined several pertinent executive privilege 1 See Archibald Cox Executive Privilege 122 U of Pa L Rev 1383 13951405 1979 See generally Mark J Rozelle Executive Privilege Presidential Powers Secrecy and Accountability 2nd Edition Revised 2002 Rozelle Mark J Rozelle Executive Privilege and Modern Presidents In Nixon s Shadow 83 Minn L Rev 1069 1999 2 See Neil Devins CongressionalExecutive Information Access Disputes A Modest ProposalDo Nothing 48 Adm LRev 109 1996 Devins 3 United States v Nixon 418 US 683 1974 Nixon v Sirica 487 F2d 700 DC Cir 1973 Senate Select Committee v Nixon 498 F2d 725 DC Cir 1974 United States v ATampT 551 F2d 384 DC Cir 1976 appeal after remand 567 F2d 121 DC Cir 1977 United States v House of Representatives 556 FSupp 150 DDC 1983 In re Sealed Case Espy 121 F3d 729 DC Cir 1997 In re Grand Jury Proceedings 5 F Supp 2d 21 DDC 1998 Judicial Watch v Department of Justice 365 F 3d 1108 D C Cir 2004 Committee on the Judiciary US House of Representatives v Miers et al Civil Action No 080409 JDB DDC July 31 2008 Miers 4 Senate Select Committee supra United States v House of Representatives supra United States v ATampT supra and Miers supra 5 Senate Select Committee supra and Miers supra CRS2 issues6 The most recent appellate court ruling involving a private group s right of access under the Freedom of Information Act to pardon documents in the custody of the Justice Department centered on a presidential claim of privilege which was rejected and further clari ed the law in this area7 The Nixon and postWatergate cases established the broad contours of the presidential communications privilege Underthose precedents the privilege which is constitutionally rooted could be invoked by the President when asked to produce documents or other materials or information that re ect presidential decisionmaking and deliberations that he believes should remain con dential If the President does so the materials become presumptively privileged The privilege however is quali ed not absolute and can be overcome by an adequate showing of need Finally while reviewing courts have expressed reluctance to balance executive privilege claims against a congressional demand for information they have acknowledged they will do so if the political branches have tried in good faith but failed to reach an accommodation However until the District of Columbia Circuit s 1997 ruling in In re Sealed Case Espy8 and its 2004 decision inJudicial Watch v Department ofJusticeg these judicial decisions had left important gaps in the law of presidential privilege which have increasingly become focal points if not the source of interbranch confrontations that has made their resolution more dif cult Among the more signi cant issues left open included whether the President has to have actually seen or been familiar with the disputed matter whether the presidential privilege encompasses documents and information developed by or in the possession of of cers and employees in the departments and agencies of the Executive Branch whether the privilege encompasses all communications with respect to which the President may be interested or is it con ned to presidential decisionmaking and if so is it limited to any particular type of presidential decisionmaking and precisely what kind of demonstration of need must be shown to justify release of materials that qualify for the privilege The unanimous panel in Espy and the subsequent reaffirmation of the principles articulated in Espy by Judicial Watch authoritatively addressed each of these issues in a manner that may have drastically alteredthe future legal playing eld in resolving such disputes A more recent dispute with Congress involving the removal and replacement of nine United States Attorneys has drawn formal claims of privilege by President George W Bush Those privilege claims have been successfully challenged in a civil suit brought by the House Judiciary Committee seeking declaratory and injunctive relief with respect to refusals by present and former senior presidential aides to appear to testify and to provide documents by two subpoenaed present and former 6 Nixon v Administrator of General Services 433 US 425 1977 7 Judicial Watch supra 8 121 F3d 729 DC Cir 1997 9 365 F 3d 1108 D C Cir 2004 CRS3 officials10 The district court s opinion may serve to further amplify the law in this area It is useful however before proceeding with a description and explication of Espy and Judicial Watch and the recent civil enforcement ruling to review and understand the prior case law and how it has affected the positions of the disputants The Watergate Cases In interbranch information disputes since the early 1980 s executive statements and positions taken in justification of assertions of executive privilege have frequently rested upon explanations of executive privilege made by the courts To better understand the executive s stance in this area and the potential impact on those positions by the Espy andJualicial Watch rulings CRS will chronologically examine the development of the judiciary s approach and describe how the executive has adapted the judicial explanations of the privilege to support its arguments In Nixon v Sirica11 the first of the Watergate cases a panel of the District of Columbia Circuit rejected President Nixon s claim that he was absolutely immune from all compulsory process whenever he asserted a formal claim of executive privilege holding that while presidential conversations are presumptively privileged 12 the presumption could be overcome by an appropriate showing of public need by the branch seeking access to the conversations In Sirica a uniquely powerful albeit undefined showing was deemed to have been made by the Special Prosecutor that the tapes subpoenaed by the grand jury contained evidence necessary to carrying out the vital function of determining whether probable cause existed that those indicted had committed crimes13 The DC Circuit next addressed the Senate Watergate Committee s effort to gain access to five presidential tapes in Senate Select Committee on Presidential Campaign Activities v Nixon14 The appeals court initially determined that the staged decisional structure established in Nixon v Sirica was applicable with at least equal force here 15 Thus in order to overcome the presumptive privilege and require the submission of materials for court review a strong showing of need had to be established The appeals court held that the Committee had not met its burden of showing that the subpoenaed evidence is demonstrably critical to the responsible fulfillment of the Committee s function 16 The court held that in view of the initiation of impeachment proceedings by the House Judiciary Committee the overlap of the investigative objectives of both committees and the fact that the impeachment committee already had the tapes sought by the Senate Committee the Select Committee s immediate oversight need for the subpoenaed tapes is from a 1 Miers supra 11 487 F2d 750 DC Cir 1973 12 487 F2d at 757 13 Id 14 498 F2d 725 DC Cir 1974 15 498 F2d at 73031 16 Id at 731 CRS4 congressional perspective merely cumulative 17 Nor did the court feel that the Committee had shown that the subpoenaed materials were critical to the performance of its legislative functions quot18 The court could discern no speci c legislative decisions that cannot responsibly be made without access to materials uniquely contained in the tapes or without resolution of the ambiguities that the presidentially released transcripts may contain 19 The court concluded that the subsequently initiated and nearly completed work of the House Judiciary Committee had in effect preempted the Senate Committee More importantly there is no indication that the findings of the House Committee on the Judiciary and eventually the House of Representatives itself are so likelyto be inconclusive or long in coming that the Select Committee needs immediate access of its own 20 The DC Circuit s view in Senate Select Committee that the Watergate committee s oversight need for the requested materials was merely cumulative in light of the then concurrent impeachment inquiry has been utilized by the Executive as the basis for arguing that the Congress interest in executive information is less compelling when a committee s function is oversight than when it is considering specific legislative proposals21 This approach however arguably misreads the carefully circumscribed holding of the court and would seem to construe too narrowly the scope of Congress investigatory powers The Senate Select Committee court s opinion took great pains to underline the unique and limiting nature of the case s factual and historical context Thus it emphasized the overriding nature of the events that have occurred since this litigation was begun and indeed since the District Court issued its decision 22 These included the commencement of impeachment proceedings by the House Judiciary Committee a committee with an express constitutional source whose investigative objectives substantially overlap those of the Senate Committee that the House Committee was presently in possession of the very tapes sought by the Select Committee making the Senate Committee s need for the tapes from a 17 Id at 732 emphasis supplied 18 Id emphasis supplied 19 Id at 733 20 Id 21 This reading of Select Committee was a persistent characteristic of the statements of the Reagan George HW Bush and Clinton Administrations See e g Letter from Attorney General William French Smith to President Reagan October 31 1981 reprinted in 5 Op OLC 27 30 1981 Smith Letter Watt Memorandum to General Counsels Consultative Group Re Congressional Requests for Con dential Executive Branch Information 13 Op OLC 185 192 1989Barr Memo letter from Attorney General Janet Reno to President Clinton September 20 1996 at 23 Reno LetterHaiti Letter from Attorney General Janet Reno to President Clinton September 16 1999 RenoFALN It is utilized in buttressing President George W Bush s June 28 2007 privilege claim with respect to demands for documents and testimony sought by the House and Senate Judiciary Committees relating to their investigations concerning the dismissal and replacement of nine US Attorneys See discussion supra at 2426 22 498 F 2d at 731 CRS5 congressional perspective merely cumulative the lack of evidence indicating that Congress itself attached any particular value to having the presidential conversations scrutinized by two committees simultaneously that the necessity for the tapes in order to make legislative judgments has been substantially undermined by subsequent events including the public release of transcripts of the tapes by the President the transfer of four of ve of the original tapes to the district court and the lack of any indication that the ndings of the House Committee on the Judiciary and eventually the House of Representatives itself are so likely to be inconclusive or long in coming that the Select Committee needs immediate access of its own 23 The appeals court concluded by reiterating the uniqueness of the case s facts and temporal circumstances We conclude that the need demonstrated by the Select Committee in the peculiar circumstances of this case including the subsequent and ongoing investigation of the House Judiciary Committee is too attenuated and too tangential to its functions to permit a judicial judgment that the President is required to comply with the Committee s subpoena 24 The Executive s position arguably ignores the roots of Congress broad investigatory powers that reach back to the establishment of the Constitution and which have been continually reaf rmed by the Supreme Court As George Mason recognized at the Constitutional Convention Congress are not only Legislators but they possess inquisitorial power They must meet frequently to inspect the Conduct of the public of ces 25 Woodrow Wilson remarked Quite as important as legislation is vigilant oversight of administration and even more important than legislation is the instruction and guidance in political affairs which the people might receive from a body which kept all national concerns suffused in a broad daylight of discussion The informing functions of Congress should be preferred even to its legislative function The argument is not only that a discussed and interrogated administration is the only pure and ef cient administration but more than that that the only really selfgoveming people is that people which discusses and interrogates its administration The Supreme Court has cited Wilson favorably on this point27 Moreover the Court has failedto make any distinction between Congress rightto executive branch information in pursuit of its oversight function and in support of its responsibility to enact amend and repeal laws In fact the Court has recognized that Congress investigatory power comprehends probes into departments of the Federal 23 Id at 73233 2quot Id at 733 It is important to note that the Select committee was established a Senate Resolution 60 1973 as a special investigation committee with no legislative authority Its sole mission was to determine the facts about the Watergate breakin and its aftermath and report to the Senate its ndings and recommendations 25 2 The Records of the Constitutional Convention of 1787 at 206 Max Farrand ed 1966 26 Woodrow Wilson Congressional Government 195 198 Meridian Books l9561885 27 See eg Hutchinson v Proxmire 443 US 111 132 1979 CRS6 Government to expose corruption inef ciency or waste 28 Thus to read Senate Select Committee as downplaying the status of oversight arguably ignores the court s very speci c reasons for not enforcing the committee s subpoena under the unique circumstance of that case and creates a distinction between oversight and legislating that has yet to be embraced by the courts Moreover the Senate Select Committee panel s demonstrably critical standard for overcoming a president s presumptive claim of privilege is not re ected in any of the subsequent Supreme Court or appellate court rulings establishing a balancing test for overcoming the quali ed presidential privilege Two months after the ruling in Senate Select Committee the Supreme Court issued its unanimous ruling in U niteal States v Nixon 29 which involved a j udicial trial subpoena to the President at the request of the Watergate Special Prosecutor for tape recordings and documents relating to the President s conversations with close aides and advisors For the rst time the Court found a constitutional basis for the doctrine of executive privilege in the supremacy of each branch within its own assigned area of constitutional duties and in the separation of powers30 But although it considered a president s communications with his close advisors to be presumptively privileged the Court rejected the President s contention that the privilege was absolute precluding judicial review whenever it is asserted31 Also while acknowledging the need for con dentiality of high level communications in the exercise of Article II powers the Court stated that when the privilege depends solely on the broad undifferentiated claim of public interest in the confidentiality of such communications a confrontation with other values arises 32 It held that absent a need to protect military diplomatic or sensitive national security secrets we nd it dif cult to accept the argument that even the very important interest in con dentiality of presidential communications is signi cantly diminished by production of materials that are essential to the enforcement of criminal statutes33 Having concluded that the claim of privilege was quali ed the Court resolved the competing interests 7 the President s need for confidentiality vs the judiciary s need for materials in a criminal proceeding 7 in a manner that preserves the essential functions of each branch 34 holding that the judicial need for the tapes as shown by a demonstrated specific need for evidence in a pending criminal trial outweighed the President s generalized interest in confidentiality 35 The Court was careful however to limit the scope of its decision noting that we are not here 28 Watkins v United States 354 US 173 187 1957 See also McGrainv Daugherty 272 US 135 1771926 Eastland v US Servicemen s Fund 421 US 491 504 n 15 1975 29 418 US 683 1974Nixon I 30 418 US 705 706 See also id at 708 711 31 Id at 705 706 708 32 Id at 706 33 Id 34 Id at 707 35 Id at 713 CRS7 concerned with the balance between the President s generalized interest in con dentiality and congressional demands for information 36 In the last of the Nixon cases Nixon V Administrator of General Services the Supreme Court again balanced competing interests in President Nixon s White House records The Presidential Recordings and Materials Preservation Act granted custody of President Nixon s presidential records to the Administrator of the General Services Administration who would screen them for personal and private materials which would be returned to Mr Nixon but preserve the rest for historical and governmental objectives The Court rejected Mr Nixon s challenge to the act which included an argument based on the presidential privilege of con dentiality 38 Although Nixon II did not involve an executive response to a congressional probe several points emerge from the Court s discussion that bear upon Congress interest in con dential executive branch information First the Court reiterated that the executive privilege it had announced in Nixon I was not absolute but quali ed39 Second the Court stressed the narrow scope of that privilege In Nixon I the Court held that the privilege is limited to communications in performance of a President s responsibilities of his of ce and made in the process of shaping policies and making decisions 40 Third the Court found that there was a substantial public interest in preserving these materials so that Congress pursuant to its broad investigative power could examine them to understand the events that led to President Nixon s resignation in order to gauge the necessity for remedial legislation 41 PostWatergate Cases Two postWatergate cases both involving congressional demands for access to executive information demonstrate both the judicial reluctance to involve itself in the essentially political confrontations such disputes represent and also the willingness to intervene where the political process appears to be failing In United States v ATampT42 the DC Circuit was unwilling to balance executive privilege claims against a congressional demand for information unless and until the political branches had tried in good faith but failed to reach an accommodation43 In that case the Justice Department had sought to enjoin ATampT s compliance with a 36 Id at 712 n 19 37 433 US 425 l977Nixon 11 38 Id at 439 39 Id at 446 40 Id at 449 citations omitted 41 Id at 453 42 567 F2d 121 DC Cir 1977 43 This was the second time the case was before the court After its initial review it was remanded to the district court to allow the parties further opportunity to negotiate an accommodation See 551 F2d 384 DC Cir 1976 CRS8 subpoena issued by a House subcommittee The subcommittee was seeking FBI letters requesting ATampT s assistance with warrantless wiretaps on US citizens allegedly made for national security purposes The Justice Department argued that the executive branch was entitledto sole control over the information because of its obligation to safeguard the national security 44 The House of Representatives as intervenor argued that its rights to the information owed from its constitutionally implied power to investigate whether there had been abuses of the wiretapping power The House also argued that the court had no jurisdiction over the dispute because ofthe Speech or Debate Clause The court rejected the con icting claims of the Executive and the Congress to absolute authority 45 With regard to the executive s claim the court noted that there was no absolute claim of executive privilege against Congress even in the area of national security The executive would have it that the Constitution confers on the executive absolute discretion in the area of national security This does not stand up While the Constitution assigns to the President a number of powers relating to national security including the function of commander in chief and the power to make treaties and appoint Ambassadors it confers upon Congress other powers equally inseparable from the national security such as the powers to declare war raise and support armed forces and in the case of the Senate consent to treaties and the appointment of ambassadors Likewise the court rejected the congressional claim that the Speech or Debate Clause was intended to immunize congressional investigatory actions from judicial review Congress investigatory power is not itself absolute 47 According to the court judicial intervention in executive privilege disputes between the political branches is improper unless there has been a good faith but unsuccessful effort at compromise48 There is in the Constitution the court held a duty that the executive and Congress attempt to accommodate the needs of each other The framers rather than attempting to define and allocate all governmental power in minute detail relied we believe on the expectation that where con icts in scope of authority arose between the coordinate branches a spirit of dynamic compromise would promote resolution of the dispute in the manner most likely to result in ef cient and effective functioning of our governmental system Under this view the coordinate branches do not exist in an exclusively adversary relationship to one another when a con ict in authority arises Rather each branch should take cognizance of an implicit constitutional mandate to seek 4 Id at 127 n17 45 Id at 128 46 Id at 128 47 Id at 129 48 Id at 12728 CRS9 optimal accommodation through a realistic evaluation of the needs of the con icting branches in the particular fact situation49 The court refused to resolve the dispute because the executive and the Congress had not yet made that constitutionally mandated effort at accommodation Instead the court encouraged negotiations in order to avoid the problems inherent in the judiciary formulating and applying standards for measuring the relative needs of the executive and legislative branches 50 The court suggested however that it would resolve the dispute if the political branches failed to reach an accommodation The courtencouraged negotiations ultimately led to a compromise Subcommittee staff was allowed to review some unedited memoranda describing the warrantless wiretaps and report orally to subcommittee members The Justice Department retained custody of the documents52 The federal district court in the District of Columbia displayed the same reluctance to intervene in an executive privilege dispute with Congress in United States v House ofRepresentatives 53 There the court dismissed a suit brought by the Justice Department seeking a declaratory judgment that the Administrator of the Environmental Protection Agency EPA acted lawfully in refusing to release certain documents to a congressional subcommittee at the direction of the President54 The Administrator basedher refusal upon President Reagan s invocation of executive privilege against a House committee probing the EPA s enforcement of hazardous waste laws The court dismissed the case without reaching the executive privilege claim on the ground that judicial intervention in a dispute concerning the respective powers of the Legislative and Executive Branches should be delayed until all possibilities for settlement have been exhausted 55 Compromise and cooperation rather than confrontation should be the aim of the parties 56 As the Court of Appeals had done in United States v ATampT the district court in United States v House of Representatives encouraged the political branches to settle their dispute rather than invite judicial intervention Only if the parties could not agree would the court intervene and resolve the interbranch dispute and even then the courts advised Judicial resolution of this constitutional claimwill never become necessary unless Administrator Gorsuch becomes a defendant in either a criminal contempt proceeding or other legal action taken by Congress 57 Ultimately the 49 Id at 127 footnote omitted 50 Id at 130 51 Id at 123 126 52 Id at 13132 53 556 FSupp 150 DDC 1983 54 Id at 151 55 Id at 152 56 Id at 153 57 Id at 152 153 CRSlO branches did reach an agreement and the court did not need to balance executive and congressional interests58 Executive Branch Positions on the Scope of Executive Privilege Reagan Through George W Bush Not surprisingly the executive branch has developed an expansive view of executive privilege in congressional investigations taking maximum advantage of the vague and essentially undefined terrain within the judicially recognized contours of the privilege Thus executive branch statements have identi ed four areas that are asserted to be presumptively covered by executive privilege foreign relations and military affairs two separate topics that are sometimes lumped together as state secrets law enforcement investigations and confidential information that reveals the executive s deliberative process with respect to policymaking Typically the executive has asserted executive privilege based upon a combination of the deliberative process exemption and one or more of the other categories As a consequence much of the controversy surrounding invocation of executive privilege has centered on the scope of the deliberative process exemption The executive has argued that at its core this category protects confidential predecisional deliberative material59 Justifications for this exemption often draw upon the language in United States v Nixon that identifies a constitutional value in the President receiving candid advice from his subordinates and awareness that any expectation of subsequent disclosure might temper needed candor60 The result has been a presumption by the executive that its predecisional deliberations are beyond the scope of congressional demand Congress will have a legitimate need to know the preliminary positions taken by Executive Branch officials during internal deliberations only in the rarest of circumstances 61 According to this view the need for the executive to prevent 58 See Devins supra 11 2 at 118120 59 See Smith letter supra note 20 5 Op OLC at 283 1 Barr Memo supra n20 13 Op OLC at 187190 RenoFALN letter supra 11 20 60 See eg 418 US at 705 See also Smith Letter supra note 20 5 Op OLC at 29 Memorandum for All Executive Department and Agency General Counsel s Re Congressional Requests to Departments and Agencies Protected By Executive Privilege September 28 1994 at 1 2 Cutler Memo Letter from Jack Quinn to Hon William A Zellif Jr October 1 1996 at 1 Quinn LetterFBI Memorandum from President Bush to Secretary of Defense Richard Cheney Re Congressional Subpoena for an Executive Branch Document August 8 1991 at 1 Bush Memo 61 Smith LetterWatt supra 11 20 at 31 see also id at 30 congressional oversight interest will support a demand for predecisional deliberative documents in the possession of the Executive Branch only in the most unusual circumstances Accord Barr Memo supra n20 at 192 Congress will seldom have any legitimate legislative interest in knowing the precise predecisional positions and statements of particular Executive Branch officials letter from Assistant Attorney General Robert Rabkin Office of Legislative Affairs D0 to Honorable John Linder Chairman House Subcommittee on Rules and Organization of the House Committee on Rules June 27 2000 at 56 Rabkin Letter The Department has a broad con dentiality interest in matters that re ect its internal deliberative process In particular we have sought to ensure that all law enforcement and litigation decisions are continued CRSll disclosure of its deliberations is at its apex when Congress attempts to discover information about ongoing policymaking within the executive branch In that case the executive has argued the deliberative process exemption serves as an important boundary marking the separation of powers When congressional oversight is used as a means of participating directly in an ongoing process of decisionmaking within the Executive Branch it oversteps the bounds of the proper legislative function 62 The executive has also argued that because candor is the principal value served by the exemption its protection should extend beyond predecisional deliberations to deliberations involving decisions already made Moreover even if the decision at issue had already been made disclosure to Congress could still deter the candor of future Executive Branch deliberations 63 Executives have also taken the position that the privilege covers confidential communications with respect to policymaking well beyond the confines of the White House and the President s closest advisors The Eisenhower Administration took the most expansive approach arguing that the privilege applied broadly to advice on official matters among employees of the 61 continued products of open frank and independent assessments of the law and facts 7 uninhibited by political and improper in uences that may be present outside the department We have long been concerned about the chilling effect that would ripple throughout government if prosecutors policy advisors at all levels and line attorneys believed that their honest opinion 7 be it good or bad may be the topic of debate in Congressional hearings or oor debates These include assessments of evidence and law candid advice on strength and weaknesses of legal arguments and recommendations to take or not to take legal action against individuals and corporate entities 62 Smith Letter Watt supra 11 20 at 3039 see also Statement of Assistant Attorney General William H Rehnquist reprinted in Executive Privilege The Withholding of Information by the Executive Hearings Before the Subcommittee on Separation of Powers of the Senate Committee on the Judiciary 92d Cong lst Sess 424 Rehnquist Statement The notion that the advisors whom he has chosen should bear some sort of a hybrid responsibility to opinion makers outside of the government which notion in practice would inevitably have the effect of diluting their responsibility to him is entirely inconsistent with our tripartite systems of government The President is entitled to undivided and faithful advice from his subordinates just as Senators and Representatives are entitled to the same sort of advice from their legislative and administrative assistants and judges to the same sort of advice from their law clerks Rabkin Letter id at n60 The foregoing concerns apply with special force to Congressional requests for prosecution and declination memoranda and similar documents These are extremely sensitive law enforcement materials The Department s attorneys are asked to render unbiased professional judgments about the merits of potential criminal and civil law enforcement cases If their deliberative documents were made subject to Congressional challenge and scrutiny we would face a grave danger that they would be chilled from providing the candid and independent analysis essential to just and effective law enforcement or just as troubling that our assessments of the strengths and weaknesses of evidence of the law before they are presented in court That may result in an unfair advantage to those who seek public funds and deprive the taxpayers of confidential representation enjoyed by other litigants 63 Smith LetterWatt supra 11 2039 5 Op OLC at 29 CRS12 executive branch64 The Nixon Administration appears to have taken a similar view arguing that the privilege applied to decisionmaking at a high governmental level but conceding that the protected communication must be related to presidential decisionmaking65 The Reagan Justice Department appears to have taken a slightly na1rower view of the scope of the privilege requiring that the protected communications have some nexus to the presidential decisionmaking process66 The George H W Bush Administration tookthe position that recommendations made to senior department officials and communications of senior policymakers throughout the executive branch were protected by executive privilege without regard to whether they involved communications intended to go to the President67 Finally the Clinton Administration took a similarly expansive position that all communications within the White House68 or between the White House and any federal department or agency69 are presumptively privileged The George W Bush Administration through presidential signing statements 70 executive orders and opinions of the Department of Justice s Office of Legal 6quot See Rozell supra nl at 39 40 65 In his prepared statement to the Subcommittee on Separation of Powers of the Senate Judiciary Committee Assistant Attorney General Rehnquist distinguished between those few executive branch witnesses whose sole responsibility is that of advising the President who should not be required to appear before Congress at all since all of their official responsibilities would be subject to a claim of privilege and ie executive branch witness whose responsibilities include the administration of departments or agencies established by Congress and from whom Congress may quite properly require extensive testimony subject to appropriate claims of privilege Rehnquist Statement supra 11 10 at 427 Moreover in colloquy with Senator Helms Mr Rehnquist seemed to accept that the privilege protected only communications with some nexus to presidential decisionmaking SENATOR ERVIN As I construe your testimony the decisionmaking process category would apply to communications between presidential advisers and the President and also to communications made between subordinates of the President when they are engaged in the process of determining what recommendations they should make to the President in respect to matters of policy MR REHNQUIST It would certainly extend that far yes Id at 43940 See also Roelle supra nl at 6566 66 See Memorandum for the Attorney General Re Con dentiality of the Attorney General s Communications in Counseling the President 6 Op OLC 481 489 l982Olson Memo 67 Bush Memo supra 11 59 at 1 Letter from General Counsel DOD Terrence O Donnell to Hon John Conyers Jr October 8 1991 at 5 O Donnell Letter 68 See eg Cutler Memo supra 11 59 at 2 69 See e g Cutler Memo supra 11 59 at 2 Communications between White House and departments or agencies including advice to or from to White House RenoFALN letter supra 11 20 70 See CRS Report RL33667 Presidential Signing Statements Constitutional and continued CRSl3 Counsel OLC has articulated a legal view of the breadth and reach of presidential constitutional prerogatives that if applied to information and documents often sought by congressional committees would stymie such inquiries72 In OLC s view under the precepts of executive privilege and the unitary executive Congress may not bypass the procedures the President establishes to authorize disclosure to Congress of classi ed privileged or even nonprivileged information by vesting lowerlevel officers or employees with a right to disclose such information without presidential authorization Thus OLC has declared tha right of disclosure statutes unconstitutionally limit the ability of the President and his appointees to supervise and control the work of subordinate officers and employees of the Executive Branch 73 The OLC assertions of these broad notions of presidential prerogatives are unaccompanied by any authoritative judicial citations The executive has acknowledged some limits to its use of executive privilege Thus presidents have stated they will not use executive privilege to block congressional inquiries into allegations of fraud corruption or other illegal or unethical conduct in the executive branch The Clinton Administration announced that in circumstances involving communications relating to investigations of personal wrongdoing by government of cials it is our practice not to assert executive privilege either in judicial proceedings or in congressional investigations 70 continued Institutional Implications by T J Halstead 71 See e g Executive Order 13233 issued by President Bush on November 1 2001 which gave current and former presidents and vice presidents broad authority to withhold presidential records and delay their release inde nitely Itvests former vice presidents and the heirs or designees of disabled or deceased presidents the authority to assert executive privilege and expands the scope of claims of privilege Hearings held by the House Committee on Government Reform in 2002 raised substantial questions as to the constitutionality of the Order and resulted in the reporting of legislation HR 4187 in the 107 Congress that would have nulli ed the Order and established new processes for presidential claims of privilege and for congressional and public access to presidential records HRept 107790 107 Cong 2nd Sess 2002 Substantially the same legislation HR 1225 passed theHouse onMarch 14 2007 See HRept 11044 110 Cong 15t Sess 2007 and was reported out of the Senate Committee on Homeland Security and Governmental Affairs on June 20 2007 without amendment and with no written report See generally Jonathan Turley Presidential Papers and Popular Government The Convergence of Constitutional and Property Theory in Claims of Ownership and Control of Presidential Records 88 Cornell L Rev 651 666696 2003 72 See Letter dated May 21 2004 to Hon Alex M Azar II General Counsel Department of Health and Human Services from Jack L Goldsmith III Assistant Attorney General Office of Legal Counsel Department of Justice available at httpwwwusdojgovolccrsmemoresponsesehtm This broad view of presidential privilege was repeated in Attorney General Mulkasey s request to the President that he claim executive privilege with respect to a House Committee subpoena for DOJ documents in an investigation by a DOJ Special Counsel in the revelation of a CIA agent s identity See letter to the President from Attorney General Mulkasey dated July 15 2008 See also discussion infra at 4041 73 Id at 3 CRSl4 and hearings 74 Similarly the Reagan Administration policy was to refuse to invoke executive privilege when faced with allegations of illegal or unethical conduct The privilege should not be invoked to conceal evidence of wrongdoing or criminality on the part of executive officers 75 A signi cant application of this policy came in the IranContra investigations when President Reagan did not assert executive privilege and even made relevant excerpts of his personal diaries available to congressional investigators76 The executive has often tied its willingness to forego assertion of privilege claims to the recognized exceptions to the deliberative process exemption stating that it would not seek to protect materials whose disclosure would not implicate or hinder the executive decisionmaking processes77 Thus factual nonsensitive materials 7 communications from the Attorney General or other executive branch official which do not contain advice recommendations tentative legal judgments drafts of documents or other material re ecting deliberative or policymaking processes 7 do not fall within the scope of materials for which executive privilege may be claimed as a basis of nondisclosure 78 Recent administrations have stated that their policy is to comply with congressional requests for information to the fullest extent consistent with the constitutional and statutory obligations of the Executive Branch 79 Executive privilege will be invoked only after careful review 80 in the most compelling circumstances 81 and only after the executive has done the utmost to reach an accommodation with Congress82 The George W Bush Administration limited the formal claims of executive privilege to those instances where the effort to 7quot Cutler Memo supra 11 59 at 1 75 Congressional Subpoenas of Department of Justice Investigative Files 8 Op OLC 315 1984 Accord Smith LetterEPA supra 11 20 at 36 These principles will not be employed to shield documents which contain evidence of criminal or unethical conduct by agency officials from proper review 76 See David Hoffman President Offers to Share Iran Sales Notes with Hill Aides Reversed on Memoir Materials Washington Post February 3 1987 at A1 77 Olson Memo supra 11 64 at 486 Rabkin Letter supra 11 60 78 Id39 but see Smith LetterEPA supra 11 20 at 32 policy does not extend to all material contained in investigative les The only documents which have been withheld are those which are sensitive memoranda or notes by attorneys and investigators re ecting enforcement strategy legal analysis lists of potential witnesses settlement considerations and similar materials the disclosure of which might adversely affect a pending enforcement action overall enforcement policy or the rights of individuals 79 Cutler Memo supra 11 59 at 1 Accord Memorandum from President Reagan for the Heads of Executive Departments and Agencies Re Procedures for Governing Responses to Congressional Requests for Information November 4 1982 Reagan Memo Rabkin Letter supra 11 60 at 12 80 Cutler Memo supra 11 59 at 1 81 Reagan Memo supra 11 74 at 1 82 Barr Memo supra 11 20 at 185 CRSlS accommodate had failed and Congress had issued a subpoena83 The duty to seek an accommodation is said to have been the result of the uncertain boundaries between executive and legislative interests84 This uncertainty imposes upon each of the branches an obligation to accommodate the legitimate needs of the other 85 and a duty to conduct good faith negotiations86 Avoiding the disclosure of embarrassing information is not a sufficient reason to withhold information from Congress87 In fact it has been averred that invocation of the privilege should not even be considered in the absence of a demonstrable justification that Executive withholding will further the public interest 88 Where negotiations have faltered and the President has made a formal claim of executive privilege the executive will likely argue as the Clinton Administration did in its invocations of executive privilege that the investigating committee has not made the showing required under Senate Select Committee v Nixon that the subpoenaed evidence is demonstrably critical to the responsible fulfillment of the Committee s functions 90 As has been indicated above since at least the Reagan Administration each executive has argued that Congress s interest in executive information is less compelling whenthe Committee s function is oversightthan when it is considering specific legislative proposals In sum then in the absence of further judicial definition of executive privilege since the Nixon cases the executive through presidential signing statements executive orders Office of Legal Counsel Opinions and most recently White House Counsel directives has attempted to effect a practical expansion of the scope of the privilege The key vehicle has been the notion of deliberative process Developed under the Freedom of Information Act to provide limited protection for the predecisional considerations of agency officials it has been melded with the recognized presidential interest in confidentiality of his communications with his close advisors to include preand postdecisional deliberations and the factual underpinnings of those decisional processes and is argued to reach policy deliberations and communications of department and agency officials and employees in which the President may have an interest The Clinton Administration sought to make this doctrinal expansion effective by centralizing scrutiny and control of all 83 Id at 185 186 See Rozelle supra n1 at 106108 8quot Rehnquist Statement supra 11 63 at 420 85 Smith LetterWatt supra 11 20 at 31 86 Reagan Memo supra 11 74 at 1 87 Rehnquist Statement supra 11 63 at 422 88 Id 89 Letter from Attorney General Janet Reno to President Clinton September 20 1996 at 23 Reno LetterHaiti letter from Attorney General Reno to President Clinton September 30 1996 at 2 Reno LetterFBI letter from Attorney General Reno to President Clinton September 16 1999 Reno LetterFALN The Acting Attorney General s opinion accompanying President George W Bush s June 28 2007 claim of executive privilege discussed in infra at 2426 relies heavily on the Senate Select Committee precedent 90 498 F2d at 731 CRSl6 potential claims of executive privilege in the White House Counsel s Office In a memorandum dated September 28 1994 from White House Counsel Lloyd Cutler to all department and agency general counsels agency heads were instructed to directly notify the White House Counsel of any congressional request for any document created in the White House or in a department or agency that contains deliberations of or advice to or from the White House which may raise privilege issues The White House Counsel is to seek an accommodation and if that does not succeed he is to consult with the Attorney General to determine whether to recommend invocation of privilege to the President The President then determines whether to claim privilege which is then communicated to the Congress by the White House Counsel91 The Cutler memo modifies President Reagan s 1982 establishment of a more decentralized procedure Under the Reagan memorandum if the head of an agency with the advice of agency counsel decided that a substantial question was raised by a congressional information request the Attorney General through the Office of Legal Counsel and the White House Counsel s Office was promptly notified and consulted Ifone or more of the presidential advisors deemed the issue substantial the President was informed and decided and the decision was to be communicated bythe agency head to the Congress The Reagan memo also contrasts with the Cutler memo in that it had a far narrower definition of what the privilege covered The Reagan memo pinpointed national security deliberative communications that form part of the decisionmaking process and other information important to the discharge of Executive Branch constitutional responsibilities92 Establishing the White House Counsel s Office as a central clearinghouse and control center for presidential privilege claims appears to have had the effect of diminishing the historic role of the Justice Department s Office of Legal Counsel as the constitutional counselor to the President and limiting agencies ability to deal informally with their congressional overseers which is likely to have been its principal objective An apparent consequence during the Clinton years was a more rapid escalation of individual interbranch information disputes clashes a widening and hardening of the differences in the legal positions of the branches on privilege issues and an increased difficulty in resolving disputes informally and quickly President Clinton formally asserted executive privilege fourteen times and resolved a number of disputes under the pressure of imminent committee actions on contempt citations and subpoena issuances93 In addition the Clinton Administration litigated and lost significant privilege cases between 1997 and 199894 One Espy to which 91 Cutler Memo supra 11 20 at 23 92 Reagan Memo supra n 71 at 2 93 See the Appendix of this Report for a compilation of executive privilege claims from the Kennedy through the George W Bush Administrations 9quot Clinton v Jones 520 US 6811997no temporary presidential immunity from civil suit for unof cial acts In re Grand Jury Subpoena Duces Tecum 112 F3d 910 8 Cir 1997 cert denied 521 US 1105 l997claims of attomeyclient and work product privilege denied In re Sealed Case 121 F3d 729 DC Cir l977claims of executive privilege continued CRS17 CRS will now turn arguably undermines many key executive assumptions about the privilege just detailed and thus may reshape the nature and course of future presidential privilege disputes Implications and Potential Impact of the Espy and Judicial Watch Rulings for Future Executive Privilege Disputes In Espy95 the appeals court addressed several important issues left unresolved bythe Watergate cases the precise parameters of the presidential executive privilege how far down the chain of command the privilege reaches whether the President has to have seen or had knowledge of the existence of the documents for which he claims privilege and what showing is necessary to overcome a valid claim of privilege The case arose out of an Office of Independent Counsel OIC investigation of former Agriculture Secretary Mike Espy When allegations of improprieties by Espy surfaced in March of 1994 President Clinton ordered the White House Counsel s Office to investigate and report to him so he could determine what action if any he should undertake The White House Counsel s Office prepared a report for the President which was publically released on October 1 1 1994 The Espy court noted that the President never saw any of the underlying or supporting documents to the report Espy had announced his resignation on October 3 to be effective on December 31 The Independent Counsel was appointed on September 9 and the grand jury issued a subpoena for all documents that were accumulated or used in preparation of the report on October 14 three days after the report s issuance The President withheld 84 documents claiming both the executive and deliberative process privileges for all documents Amotion to compel was resisted on the basis of the claimed privileges After in camera review the district court quashed the subpoena but in its written opinion the court did not discuss the documents in any detail and provided no analysis of the grand jury s need for the documents The appeals court panel unanimously reversed At the outset the court s opinion carefully distinguishes between the presidential communications privilege and the deliberative process privilege Both the court observed are executive privileges designed to protect the confidentiality of executive branch decisionmaking But the deliberative process privilege that applies to executive branch officials generally is a common law privilege which requires a lower threshold of need to be overcome and disappears 9quot continued rejected In re Sealed Case 124 F3d 230 DC Cir 1997claims of attomeyclient and work product privilege denied In re Sealed Case 148 F 3d 1073 DC Cir cert denied 525 U S990 1998 claim of protective function privilege denied In re Bruce R Lindsey Grand Jury Testimony 148 F 3d 1100 DC Cir 1998 claims of attomeyclient and work product privilege denied 95 121 F3d 729 DC Cir 1997 CRS18 altogether when there is any reason to believe government misconduct has occurred 96 On the other hand the court explained the presidential communications privilege is rooted in constitutional separation of powers principles and the President s unique constitutional role and applies onlyto direct decisionmaking by the President 97 The privilege may be overcome only by a substantial showing that the subpoenaed materials likely contain important evidence and that the evidence is not available with due diligence elsewhere 98 The presidential privilege applies to all documents in their entirety99 and covers nal and postdecisional materials as well as predeliberative ones100 Turning to the chain of command issue the court held that the presidential communications privilege must cover communications made or received by presidential advisers in the course of preparing advice for the President even if those communications are not made directly to the President The court rested its conclusion on the President s dependence on presidential advisers and the inability of the deliberative process privilege to provide advisers with adequate freedom from the public spotligh and the need to provide suf cient elbow room for advisers to obtain information from all knowledgeable sources 101 Thus the privilege will apply both to communications which these advisers solicited and received from others as well as those they authored themselves The privilege must also extend to communications authored or received in response to a solicitation by members of a presidential adviser s staff 102 The court however was acutely aware of the dangers to open government that a limitless extension of the privilege risks and carefully cabined its reach by explicitly con ning it to White House staff and not staff in the agencies and then only to White House staff that has operational proximity to direct presidential decisionmaking We are aware that such an extension unless carefully circumscribed to accomplish the purposes of the privilege could pose a signi cant risk of 96 121 F3d at 745 74639 see also id at 737738 Where there is reason to believe the documents sought may shed light on government misconduct the deliberative process privilege is routinely denied on the grounds that shielding internal government deliberations in this context does not serve the public interest in honest effective governmen 97 Id at 745 752 See also id at 753 these communications nonetheless are ultimately connected with presidential decisionmaking 98 Id at 754 See also id at 757 99 In contrast the deliberative process privilege does not protect documents that simply state or explain a decision the government has already made or material that is purely factual unless the material is inextricably intertwined with the deliberative portions of the materials so that disclosure would effectively reveal the deliberations 121 F3d at 737 10 Id at 745 101 Id at 752 102 CRS19 expanding to a large swath of the executive branch a privilege that is bottomed on a recognition of the unique role of the President In order to limit this risk the presidential communications privilege should be construed as narrowly as is consistent with ensuring that the con dentiality of the President s decisionmaking process is adequately protected Not every person who plays a role in the development of presidential advice no matter how remote and removed from the President can qualify for the privilege In particular the privilege should not extend to staff outside the White House in executive branch agencies Instead the privilege should apply only to communications authored or solicited and received by those members of an immediate White House advisor s staff who have broad and signi cant responsibility for investigation and formulating the advice to be given the President on the particular matter to which the communications relate Only communications at that level are close enough to the President to be revelatory of his deliberations or to pose a risk to the candor of his advisers See AAPS 997 F2d at 910 it is operational proximity to the President that matters in determining whether the President s con dentiality interests is implicatedemphasis omitted Of course the privilege only applies to communications that these advisers and their staff author or solicit and receive in the course of performing their function of advising the President on of cial government matters This restriction is particularly important in regard to those of cials who exercise substantial independent authority or perform other functions in addition to advising the President and thus are subject to F OIA and other open government statutes See Armstrong v Executive O iee 0f the President 90 F3d 553 558 DC Cir 1996 cert deniedi US 7 117 SCt 1842 137 L Ed2d 1046 1997 The presidential communications privilege should never serve as a means of shielding information regarding governmental operations that do not call ultimately for direct decisionmaking by the President If the government seeks to assert the presidential communications privilege in regard to particular communications of these dual hat presidential advisers the government bears the burden of proving that the communications occurred in conjunction with the process of advising the President103 The appeals court s limitation of the presidential communications privilege to direct decisionmaking by the President makes it imperative to identify the type of decisionmaking to which it refers A close reading of the opinion makes it arguable that it is meant to encompass only those functions that form the core of presidential authority involving what the court characterized as quintessential and nondele gable Presidential power 104 In the case before it the court was speci cally referring to the President s Article II appointment and removal power which was the focal point of the advice he sought in the Espy matter But it seems clear from the context of the opinion that the description was meant to be in juxtaposition with the appointment and removal power and in contrast with presidential powers and responsibilities that can be exercised or performed without the President s direct involvement pursuant to a presidential delegation of authority or statutory framework 105 The reference the court uses to illustrate the latter category is the President s Article II 103 Id footnote omitted 104 Id at 752 105 Id at 75253 CRS20 duty to take care that the laws are faithfully executed a constitutional direction that the courts have consistently held not to be a source of presidential power but rather an obligation on the President to see to it that the will of Congress is carried out by the executive bureaucracy106 The appeals court then would appear to be con ning the parameters of the newly formulated presidential communications privilege by tying it to those Article 11 functions that are identi able as quintessential and nondelegable which would appear to include in addition to the appointment and removal powers the commanderinchief power the sole authority to receive ambassadors and other public ministers the power to negotiate treaties and the power to grant pardons and reprieves On the other hand decisionmaking vested by statute in the President or agency heads such as rulemaking environmental policy consumer protection workplace safety and labor relations among others would not necessarily be covered Of course the President s role in supervising and coordinating but not displacing decisionmaking in the executive branch remains unimpeded But his communications in furtherance of such activities would presumably not be cloaked by constitutional privilege Such a reading of this critical passage of the court s opinion is consonant with the court s view of the source and purpose of the presidential communications privilege and its expressed need to con ne it as narrowly as possible Relying on Nixon I the Espy court identi es the President s Article II powers and responsibilities as the constitutional basis of the presidential communications privilege Since the Constitution assigns these responsibilities to the President alone arguably the privilege of con dentiality that derives from it also should be the President s alone 107 Again relying on Nixon I the court pinpoints the essential purpose of the privilege Tlhe privilege is rooted in the need for con dentiality to ensure that presidential decisionmaking is of the highest caliber informed by honest advice and knowledge Con dentiality is what ensures the expression of candid objective and even blunt or harsh opinions and the comprehensive exploration of all policy alternatives before a presidential course of action is selected 108 The limiting safeguard is that the privilege will apply in those instances where the Constitution provides that the President alone must make a decision The presidential communications privilege should never serve as a means of shielding information regarding governmental operations that do not call ultimately for direct decisionmaking by the President 109 106 See eg Kendall ex rel Stokes v United States 37 US 12 Pet 522 612613 1838 Youngstown Sheet amp Tube Co v Sawyer 343 US 579 587 1952 Myers v United States 272 US 52 177 1926Holmes J dissenting National Treasury Employees Union v Nixon 492 F2d 587 604 DC Cir 1974 107 121 F3d at 748 108 Id at 750 109 Id at 752 CRS2l The District of Columbia Circuit s 2004 decision in Judicial Watch Inc v Department of Justice110 appears to lend substantial support to the aboveexpressed understanding of Espy Judicial Watch involved requests for documents concerning pardon applications and pardon grants reviewed by the Justice Department s Of ce of the Pardon Attorney and the Deputy Attorney General for consideration by President Clinton 1 Some 4300 documents were withheld on the grounds that they were protected by the presidential communications and deliberative process privileges The district court held that because the materials sought had been produced for the sole purpose of advising the President on a quintessential and non delegable Presidential power ithe exercise of the President s constitutional pardon authority 7 the extension of the presidential communications privilege to internal Justice Department documents which had not been solicited and received by the President orthe Of ce of the President was warranted112 The appeals court reversed concluding that internal agency documents that are not solicited and received by the President or his Of ce are instead protected against disclosure if at all by the deliberative process privilege 113 Guided by the analysis of the Espy ruling the panel majority emphasized that the solicited and received limitation is necessitated by the principles underlying the presidential communications privilege and a recognition of the dangers of expanding it too far 114 Espy teaches the court explained that the privilege may be invoked only when presidential advisers in close proximity to the President who have signi cant responsibility for advising him on nondelegable matters requiring direct presidential decisionmaking have solicited and received such documents or communications or the President has received them himself In rejecting the Govemment s argument that the privilege should be applicable to all departmental and agency communications related to the Deputy Attorney General s pardon recommendations for the President the panel majority held that Such a brightline rule is inconsistent with the nature and principles of the presidential communications privilege as well as the goal of serving the public interest Communications never received by the President or his Of ce are unlikely to be revelatory of his deliberations nor is there any reason to fear that the Deputy Attorney General s candor or the quality of the Deputy s pardon recommendations would be sacri ced if the presidential communications privilege did not apply to internal documents Any pardon documents reports or recommendations that the Deputy Attorney General submits to the Of ce of the President and any direct communications the Deputy or the Pardon Attorney may have with the White House Counsel or other immediate Presidential 110 365 F3d 1108 DC Cir 2004 The panel split 21 with Judge Rogers writing for the majority and Judge Randolph dissenting 1 The President has delegated the formal process of review and recommendation of his pardon authority to the Attorney General who in turn has delegated it to the Deputy Attorney General The Deputy Attorney General oversees the work of the Office of the Pardon Attorney 1 365 F3d at 110912 31d at111211141123 1 Id at 1114 CRS22 advisers will remain protected It is only those documents and recommendations of Department staff that are not submitted by the Deputy Attorney General for the President and are not otherwise received by the Office of the President that do not fall under the presidential communications privilege115 Indeed the Judicial Watch panel makes it clear that the Espy rationale would preclude cabinet department heads from being treated as being part of the President s immediate personal staff or as some unit of the Of ce of the President Extension of the presidential communications privilege to the Attorney General s delegatee the Deputy Attorney General and his staff on down to the Pardon Attorney and his staff with the attendant implication for expansion to other Cabinet of cers and their staffs would as the court pointed out in In re Sealed Case pose a significant risk of expanding to a large swatch of the executive branch a privilege that is bottomed on a recognition of the unique role of the President The Judicial Watch majority took great pains to explain why Espy and the case before it differed from the Nixon and postWatergate cases According to the court until In re Sealed Case the privilege had been tied speci cally to direct communications of the President with his immediate White House advisors 117 The Espy court it explained was for the rst time confronted with the question whether communications that the President s closest advisors make in the course of preparing advise for the President and which the President never saw should also be covered by the presidential privilege The Espy court s answer was to espouse a limited extension of the privilege downthe chain of command beyond the President to his immediate White House advisors only recognizing the need to ensure that the President would receive full and frank advice with regard to his nondelegable appointment and removal powers but was also wary of undermining countervailing considerations such as openness in government Hence the Espy court determined that while communications authored or solicited and received by immediate White House advisors in the Office of the President could qualify under the privilege communications of staff outside the White House in executive branch agencies that were not solicited and received by such White House advisors could not 118 The situation before the Judicial Watch court tested the Espy principles While the presidential decision involved 7 exercise of the President s pardon power 7 was certainly a nondelegable core presidential function the operating officials involved the Deputy Attorney General and the Pardon Attorney were deemed to be too remote from the President and his senior White House advisors to be protected The court conceded that functionally those officials were performing a task directly related to the pardon decision but concluded that an organizational test was more appropriate 115Id at 1117 6 Id at 112122 117Id at 1116 8 Id at 1116117 CRS23 for con ning the potentially broad sweep that would result from a functional test Under the latter test there would be no limit to the coverage of the presidential communications privilege In such circumstances the majority concluded the lesser protections of the deliberative process privilege would have to suffice119 That privilege was found insufficient and the appeals court ordered the disclosure of the 4300 withheld documents It may be noted that in at least one analogous instance the White House divulged documents sought by a congressional committee which argued the more limited reading of Espy When Espy was decided the House Resources Committee was in the midst of an inquiry of President Clinton s utilization of the Antiquities Act of 1906120 which authorizes the President in his discretion to declare by public proclamation objects of historic or scienti c interest on federal lands to be national monuments by reserving parcels that shall be confined to the smallest area compatible with the proper care and management to the objects to be protected The act establishes no special procedures for the decision to declare a national monument and contains no provision for judicial review Shortly before the 1996 presidential election President Clinton reserved 17 million acres in Utah by proclamation Central to the Committee s inquiry as to the propriety and integrity of the decisionmaking process that led to the issuance of the presidential proclamation were the actions of the Council on Environmental Quality CEQ an office within the Executive Office of the President with about the same degree of advisory proximity as that of the White House Counsel s Office Requests for physical production of documents from CEQ met with limited compliance an offer to view 16 documents at the White House The Committee believed that it required physical possession in order to determine the propriety of the process and issued a subpoena which was not complied with on the return date During intense negotiations the White House claimed the documents were covered by the presidential communications privilege even as defined by Espy In a letter to the Committee the White House Counsel s Office argued that the opinion did not confine the privilege to just core Article II powers but included presidential decisionmaking encompassed within the Article II duty to take care that the laws be faithfully executed It asserted that since the President had the sole authority to designate a monument by law that decisional process including deliberations among and advice of White House advisers was covered The Committee in reply letters disagreed arguing that Espy would not encompass a statutory delegation of decisional authority On the eve of a scheduled Committee vote on a resolution of contempt the White House produced all the documents121 Id at 111824 120 16 USC 431 2000 1 See 143 Cong Rec E2259 2272 daily ed November 9 1997Remarks of Hon James V Hansen presenting staff study of committee actions and documents in regard to the establishment of the Grand StaircaseEscalante National Monument See also Ruth Larson White House Yields Papers on Utah Wilderness Decision Wash Times October 23 1997 A3 Of course the White House action cannot be deemed a concession of the legal argument in the absence of an explanation for its decision to disclose the material CRS24 The na1rower reading of Espy by the House Committee also accommodates the need of Congress for exibility in assigning tasks for executive ful llment It is of course the predominant practice of Congress to delegate the execution of laws to the heads of departments and agencies But there are occasions when the nature of the decisionmaking is deemed so sensitive or important or unique that direct presence of presidential authority is appropriate Where the exercise of such authority derives solely from the statutory delegation and does not find its basis in one of the socalled core constitutional powers of the President it is a reasonable expectation of the Congress that it will be able to determine whether and how the legislative intent has been carried out just as it does with its assignments to the departments and agencies A view that any delegation of decisionmaking authority directly to the President will thereby cloak it from congressional scrutiny is not only anomalous but arguably counterproductive of interbranch coordination cooperation and comity as it would discourage such delegations122 Of course further judicial development of the principles enunciated in Espy may alter this view of its scope Recent Developments George W Bush Claims of Executive Privilege In early 2007 the House Judiciary Committee and its Subcommittee on Commercial and Administrative Law commenced an inquiry into the propriety of the termination and replacement of a number of United States Attorneys Six hearings and numerous interviews were held by the committees between March and June 2007 essentially focusing on testimony with respect to actions of present and former Department of Justice DOJ of cials and employees as well as DOJ documents relating to the matter On March 21 2007 the House Subcommittee authorized Chairman John Conyers Jr to issue subpoenas to a number of present and former White House Of cials for documents and testimony On June 13 2007 Chairman Conyers issued subpoenas to White House Chief of Staff Joshua Bolten as custodian of White House documents returnable on June 28 2007 and to former White House Counsel Harriet Miers returnable on July 12 2007 On June 27 2007 White House Counsel Fred F Fielding at the direction of President Bush advised the Chairmen of the House and Senate Judiciary Committees that document subpoenas issued to the White House custodian of documents and to two former White House of cials Sara M Taylor subpoenaed by the Senate Judiciary Comittee and Harriet Miers relating to those Committees investigations of the dismissal and replacement of nine U S attorneys in 2006 had been deemed by the President subject to executive privilege and that the subpoena recipients have been directed not to produce any documents The Fielding letter also noted that the testimony sought from Ms Miers and Ms Taylor was also subject to a valid claim m The notion that a congressional delegation of administrative decisionmaking authority is implicitly a concurrent delegation of authority to the President is effectively countered by Professor Kevin Stack in quotThe President s Statutory Power to Administer the Laws 106 Colum L Rev 263 2006 CRS25 of Executive Privilege and would be asserted if the matter could not be resolved before dates scheduled for their appearances123 Accompanying the Fielding letter was a legal memorandum prepared by Acting Attorney General Paul D Clement for the President detailing the legal basis for a claim of executive privilege124 The memo identi es three categories of documents being sought 1 internal White House Communications 2 communications by White House Of cials with individuals outside the Executive Branch including individuals inthe Legislative Branch and 3 communications between White House and Justice Department of cials125 With respect to internal White House communications which are saidto consist of discussions of the wisdom of removal and replacement proposals which US Attorneys should be removed and possible responses to Congressional and media inquiries such discussions are claimed to be the types of internal deliberations among White House of cials that fall squarely within the scope of executive privilege since their nondisclosure promote s sound decisionmaking by ensuring that senior Government of cials and their advisors may speak frankly and candidly duringthe decisionmaking process citing US v Nixon Since it is argued what is involved is the exercise of the presidential power to appoint and remove of cers of the United States a quintessential and nondelegable Presidential power citing Espy the President s protected con dentiality interests are particularly strong in this instance As a consequence an inquiring congressional committee would have to meet the standard established by the Senate Select Committee decision requiring a showing that the documents and information are demonstrably critical to the responsible ful llment of the Committee s function 126 Thus it is claimed there is doubt whether the Committees have oversight authority over deliberations essential to the exercise of this core presidential power or that their interests justify overriding a claim of executive privilege as to the matters at issue 127 With respect to category 2 matters involving communications by White House of cials with individuals outside the White House the Clement memo asserts that con dentiality interests undergirding the privilege are not diminished if the President or his close advisors have to go outside the White House to obtain information to make an informed decision particularly about a core presidential power Again Espy and Senate Select Committee are referred as supporting authority As to the final category respecting communications between the Justice Department and the White House concerning proposals to dismiss and replace US Attorneys it is claimed that such communications are deliberative and clearly fall within the scope of executive privilege The President s need to protect 1 Letter dated June 28 2007 to Chairman Conyers and Leahy from Fred F Fielding Counsel to the President 1 Memorandum dated June 27 2007 for the President from Paul D Clement Solicitor General and Acting Attorney General Clement Memo 125 Clement Memo at l 1 Clement Memo at 2 7 Id at 3 CRS26 deliberations about the selection of US Attorneys is compelling particularly given Congress lack of legislative authority over the nomination or replacement of US Attorneys citing Espy and Senate Select Committee 128 The privilege is asserted to extend to White House DOJ communications that have been previously disclosed to the Committees by the Department An argument that a waiver may have occurred is contrary to relevant legal principles that should and do encourage rather than punish such accommodations by recognizing that Congress need for such documents is reduced to the extent similar materials have been provided voluntarily as part of the accommodation process Since the Committees have these documents seeking the relevant communications would be cumulative under Senate Select Committee 129 This rationale is argued to support the lack of any need for the testimony of the former White House officials subpoenaed Congressional interest in investigating the replacement of U S Attorneys clearly falls outside its core constitutional responsibilities and any legitimate interest Congress may have in the disclosed communications has been satisfied by the Department s extraordinary accommodation involving the extensive production of documents to the Committees interviews and hearing testimony concerning these communications As the DC Circuit has explained because legislative judgements normally depend more on the predicted consequences of proposed legislative actions and their political acceptability Congress will rarely need or be entitled to a precise reconstruction of past events to carry out its legislative responsibilities Senate Select Comm 498 F 2d at 732130 On June 29 2007 Chairman Conyers and Senate Judiciary Committee Chairman Patrick Leahy jointly responded to the Fielding letter and Clement memorandum Characterizing the White House stance as based on blanket executive privilege claims which makes it difficult for the Committees to determine where privilege truly does and does not apply the Committees demanded that they be provided with a detailed privilege log that includes for each document withheld a description of the nature source subject matter and date of the document the name and address of each recipient of an original or copy of the document and the date received the name and address of each additional person to whom any of the contents of the document was disclosed along with the date and manner of disclosure and the speci c basis for the assertion of privilege A deadline for receipt ofthe privilege log was set for July 9 2007 On July 9 2007 the White House Counsel refused to comply On that same date counsel to Ms Miers informed Chairman Conyers that pursuant to letters received from the White House Counsel Miers would not testify or produce documents and the next day July 10 announced that Miers would not appear at all That same day the DOJ office of Legal Counsel OLC issued an opinion that Ms Miers is absolutely immune from compulsion to testify before the Committee on 8 Id at 56 129 Id at 6 13 Id at 67 CRS27 this matter and therefore is not required to appear to testify about the subject 131 Citing previous OLC opinions the opinion asserts that sincethe President is the head of one of the independent branches of the federal government Ifa congressional committee could force the President s appearance fundamental separation of powers principles fincluding the President s independence and autonomy from Congress7 would bethreatened As a consequence the same separation of powers principles that protect a President from compelled congressional testimony also apply to senior presidential advisors because such appearances would be tantamount to the President himself appearing The fact that Ms Miers is a former counsel to the President does not alter the analysis since a presidential advisor s immunity is derivative of the President s Neither Ms Miers nor Mr Bolten complied on the return dates of their subpoenas On July 12 2007 the House Subcommittee met and Chairman Sanchez issued a ruling rejecting Ms Miers privilege claims with respect to failing to appear produce documents and testify which was upheld by a 75 vote On July 19 the Subcommittee Chair ruled against Mr Bolten s privilege claims with respect to his failure to produce documents which was upheld by a 75 vote On July 25 the full Judiciary Committee voted 2 ll7 to issue a report to the House recommending that a resolution of contempt of Congress against Miers and Bolten be approved Thereafter the White House announced that it would order the United States Attorney for the District of Columbia not to present the contempt of Congress citation for grand jury consideration The Judiciary Committee filed its Report formally reporting a contempt violation to the House in November 2007132 After further attempts at accommodation failed the matter was brought to the oor of the House on February 14 2008 which voted 223 to 32 to hold Ms Miers and Mr Bolten in contempt of Congress for their willful failure to comply with the Committee s subpoenas At the same time the House passed three resolutions HRes 979 directed the Speaker to certify the report of the Judiciary Committee detailing the refusals of Ms Miers to appear before to testify before and to produce documents to the Committee and Mr Bolten s refusal to produce documents as required by subpoenas to the United States Attorney for the District of Columbia for presentation to a grand jury pursuant to 2 USC 192 and 194133 HRes 980 in apparent anticipation that the criminal contempt citation would not be presented to the grand jury by the US Attorney authorized the Chairman of the Judiciary Committee to initiate civil judicial proceedings in federal court to seek a declaratory judgment affirming the duty of any individual to comply with any subpoena that is the subject of HRes 979 and to issue appropriate injunctions to achieve compliance The resolution also authorized the House General Counsel to 1 Memorandum for the Counsel to the President Re Immunity of Former Counsel to the President from Compelled Congressional Testimony from Principal Deputy Assistant Attorney General Office Legal Counsel DOJ dated July 10 2007 OLC Immunity Opinion 1 HRept 110423 llO39h Cong lst Sess 2007 1 HRes 979 llO39h Cong February 14 2008 CRS28 represent the Committee in any such litigation HRes 982 adopted both HRes 979 and HRes 980 On February 28 2008 the Speaker certifiedthe Committee s Report to the US Attorney On February 29 2008 Attorney General Mukasey advisedthe Speaker that the Department will not bring the congressional contempt citations before a grand jury or take any other action to prosecute Mr Bolten or Ms Miers On March 10 2008 the House General Counsel led a civil action for declaratory judgement and injunctive relief against Ms Miers and Mr Bolten134 The suit sought a declaration by the court that 1 Ms Miers is not immune from the obligation to appear before the Committee in response to a duly authorized issued and served Committee subpoena 2 Ms Miers and Mr Bolten produce privilege logs identifying all documents withheld on grounds of executive privilege and 3 Ms Miers and Mr Bolten s claims are improper in the context of communications not involving the President or undertaken directly in preparation for advising the President and that Ms Miers and Mr Bolten s claims of executive privilege are in any event overcome by the Committee s demonstrated specific need for the subpoenaed testimony and comments In addition the Committee sought an order directing Ms Miers to appear before the Committee to respond to questions and to invoke executive privilege if and when appropriate to have Ms Miers and Mr Bolten provide detailed privilege logs with respect to documents claimed to be privileged and for both to produce all nonprivileged documents subject to the subpoenas On April 10 2008 the House General Counsel filed a Motion for Partial Summary Judgment seeking a declaration that 1 Ms Miers failure to appear at all in response to the Committee s subpoena was without legal justification 2 that she must appear before the Committee and assert privilege claims in response to questions as appropriate but must testify about subjects not covered by privilege 3 that the failure of both Ms Miers and Mr Bolten to supply privilege logs with respect to withheld documents is legally unjustified and 4 that both be ordered to provide detailed privilege logs with respect to documents claimed to be privileged and to produce all relevant nonprivileged documents On July 31 2008 the district court essentially granted the Committee s motion for partial summary judgment in its entirety135 The court s lengthy opinion 13quot Committee on the Judiciary United States House of Representatives v Harriet Miers and Joshua Bolten Case No 0800409 DDC JDB Miers 135 The court declined to order Ms Miers and Mr Bolten to provide detailed privilege logs with respect to documents claimed to be covered by executive privilege holding that while such logs have great practical utility there is no applicable statute or controlling case law that would provide a ready ground by which to force the Executive to make such a production strictly in response to a congressional subpoena Miers slip opinion at 92 emphasis in original The court warned however that both the court and the parties will need some way to evaluate privilege assertions going forward in the context of this litigation Id The court particularly noted that if it has to decide the merits of a privilege claim the government will need a better description of the documents than the one found continued CRS29 principally dealt with the Executive s claims that the suit should be dismissed because the Committee 1 lacked standing 2 had not stated a cause of action authorizing the suit and 3 was inappropriately involving the court in a dispute between the political branches of a type of that traditionally has been resolved by negotiation and accommodation by the parties The court rejected the Executive s justiciability claims finding both standing and an implied cause of action in the Constitution s institutional commitment to the Congress in Article I of the power of inquiry observing that the Supreme Court has consistently recognized that the power carries with it the process to enforce i which is an essential and appropriate auxiliary to the legislative function and that issuance of a subpoena pursuant to an authorized investigation is an indispensable ingredient of law making 136 In rejecting the suggestion that the court exercise its equitable discretion not to involve itself in a political dispute between the branches the court observed that numerous courts since the initial Watergate rulings had found it appropriate to attempt to resolve subpoena disputes raising privilege and immunity questions in both civil and criminal contexts involving the political branches in circumstances where it appeared only judicial intervention could prevent a stalemate that could result in a paralysis of government The court noted that both parties conceded that an impasse had been reached and observed Although the identity of the litigants in this case necessitates that the Court proceed with caution that is not a convincing reason to decline to decide a case that presents important legal questions Rather than running roughshod over separation of powers principles the Court believes that entertaining this case will reinforce them Two parties cannot negotiate in good faith when one side asserts legal privileges but insists that they cannot be tested in court in the traditional manner That is true whether the negotiating parties are private rms or the political branches of the federal government Accordingly the Court will deny the Executive s motion to dismiss137 Turning to the sole merits issue raised by the Committee s motion for partial summary judgement the Executive s claim that present and past senior advisers to the President are absolutely immune from compelled congressional process the court s conclusion was an unequivocal rejection of the govemment s position The Executive cannot identify a single judicial opinion that recognizes absolute immunity for senior presidential advisors in this or any other context That 135 continued in Mr Clement s letter of June 27 2007 The Clement letter is discussed in the text supra at pp 2426 With this admonition the court ordered that the defendants shall provide to the plaintiff a speci c description of any documents withheld from production on the basis of executive privilege consistent with the terms of the Memorandum Opinion issued on this date Miers Order at 12 136 Miers slip opinion at 36 citing McGrain v Daugherty supra and Eastland v United States Servicemen s Fund supra 137151 at 77 78 For an indepth discussion of the implications and importance of the court s justiciability rulings see CRS Report RL34097 Congress ContemptPower Law History Practice and Procedure by Morton Rosenberg and Todd B Tatelman CRS30 simple yet critical factbears repeating the asserted absolute immunity claim here is entirely unsupported by existing case law In fact there is Supreme Court authority that is all but conclusive on this question and that powerfully suggests that such advisors do not enjoy absolute immunity The Court therefore rejects the Executive s claim of absolute immunity for senior presidential aides138 At the outset the court noted that a 1950 Supreme Court ruling in United States V Bryan139 establishedthat if compliance with a congressional subpoena requirement is ignored the great power of testimonial compulsion so necessaryto the effective functioning of courts and legislatures would be a nullity 140 In attempting to explain why compliance is to be excused in this instance the Executive argued that since the President himself is absolutely immune to compelled congressional testimony close advisers to the President himself must be regarded as his alter ego and be entitled to the same absolute immunity Forcing such close advisors to testify before Congress would be tantamount to compelling the President to do so The court responded that the same line of argument had been rejected by the Supreme Court in Harlow v F z39tzgeralal141 a suit for damages against senior White House aides arising out of the defendants official actions The aides claimed they were entitled to a blanket protection of absolute immunity as an incident of their offices as Presidential aides 142 Recognizing that absolute immunity had been extended to legislators judges prosecutors and the President himself the Supreme Court rejected extending such immunity further emphasizing that for executive officials in general however our cases make plain that quali ed immunity represents the norm 143 The High Court rejected the argument that it had accorded derivative immunity to legislative aides in Speech or Debate cases as sweep ing too far noting that even cabinet members are not entitled to absolute immunity 144 The Harlow Court made the concession that a presidential aide could be accorded absolute immunity if it was shown that the responsibilities of his office embraced a sensitive function such as foreign policy or national security and that he was discharging the protected functions when performing the act for which liability is asserted145 The M iers district court concluded that in this matter since there was no involvement of national security or foreign policy concerns neither Ms Miers nor Mr Bolten s close proximity to the President is sufficient under Harlow to provide either absolute or quali ed immunity 146 138 Id at 78 139 339 US 323 1950 140 Id at 331 141 457 US 800 1982 142 Id at 808 143 Id at 807 144 Id at 810 145Id at 812813 6 Miers slip opinion at 8182 87 CRS3l In response to the Executive s claim that without absolute immunity there would be a chilling effect on the candid and frank advice advisers would provide a Chief Executive the court stated The prospect of being hauled in front of Congress 7 daunting as it may be 7 would not necessarily trigger the chilling effect that the Executive predicts Senior executive officials often testify before Congress as a normal part of their jobs and forced testimonybefore Congress does not implicate the same concern regarding personal financial exposure as does a damages suit Signi cantly the Committee concedes that an executive branch of cial may assert executive privilege on a questionbyquestion basis as appropriate That should serve as an effective check against public disclosure of truly privileged communications thereby mitigating any adverse impact on the quality of advice that the President receives In any event the historical record produced by the Committee reveals that senior advisors to the President have often testi ed before Congress subject to various subpoenas dating back to 1973 See Auerbach Decl W 23 Thus it would hardly be unprecedented for Ms Miers to appear before Congress to testify and assert executive privilege where appropriate Still it is noteworthy that in an environment where there is no judicial support whatsoever for the Executive s claim of absolute immunity the historical record also does not re ect the wholesale compulsion by Congress of testimony from senior presidential advisors that the executive fears147 Next the district court rejectedthe claim thatNixon v United States established that a president s immunity is quali ed and not absolute only when judicial resolution of a criminal justice matter concerned148 Here the court emphasized the Executive argued that what was involved was a peripheral exercise of Congress power not a core function of another branch The court responded Congress s power of inquiry is as broad as its power to legislate and lies at the very heart of Congress s constitutional role Indeed the former is necessary to the proper exercise of the latter according to the Supreme Court the ability to compel testimony is necessary to the e ective functioning of courts and legislatures Bryan 339 US at 331 emphasis added Thus Congress s use of and need for vindication of its subpoena power in this case is not less legitimate or important than was the grand jury s in United States v Nixon Both involve core functions of a coequal branch of the federal government and for the reasons identi ed in Nixon the President may only be entitled to a presumptive rather than absolute privilege here And it is certainly the case that if the President is entitled only to a presumptive privilege his close advisors cannot hold the superior card of absolute immunity A claim of absolute immunity from compulsory process cannot be erected by the Executive as a surrogate for the claim of absolute privilege already rmly rejected by the courts Presidential autonomy such as it is cannot mean that the Executive s actions are totally insulated from scrutiny by Congress That would eviscerate the Congress s oversight functions149 71d at 8384 Emphasis in original 8 Nixon 1 supra 418 US at 707708 149 Id at 8485 CRS32 The court recognized that the effect of a claim of absolute privilege for close advisors was to make the President the judge of the parameters of his own quali ed privilege Permitting the Executive to determine the limits of its own privilege would impermissiny transform the presumptive privilege into an absolute one yet that is what the Executive seeks through its assertion of Ms Miers absolute immunity from compulsory process That proposition is untenable and cannot be justi ed by appeals to Presidential autonomy 150 Finally the district court rejected the govemment s fallback position that even if Ms Miers is not entitled to absolute immunity she should be accorded quali ed immunity The court dismissed the argument relying on the requirements established by Harlow This inquiry does not involve sensitive topics of national security or foreign affairs Congress moreover is acting pursuant to a legitimate use of its investigative authority Notwithstanding its best efforts the Committee has been unable to discover the underlying causes of the forced terminations of the US Attorneys The Committee has legitimate reasons to believe that Ms Miers s testimony can remedy that dificiency There is no evidence that the Committee is merely seeing to harass Ms Miers by calling her to testify Importantly moreover Ms Miers remains able to assert privilege in response to any speci c question or subject matter For its part the Executive has not offered any independent reasons that Ms Miers should be relieved from compelled congressional testimony beyond its blanket assertion of absolute immunity The Executive s showing then does not support either absolute or quali ed immunity in this case 151 The court concluded that its rejection of a claim of absolute immunity rested on two premises Such a claim wouldtransform the President s quali ed immunity into an absolute one and if such a claim were to prevail it would cover even non privileged executive information There are powerful reasons supporting the rejection of absolute immunity as asserted by the Executive here If the Court held otherwise the presumptive presidential privilege could be transformed into an absolute privilege and Congress legitimate interest in inquiry could be easily thwarted Indeed even the Speech or Debate context which has an explicit textual basis and confers absolute immunity Members of Congress must still establish that their actions were legislative in nature before invoking the protection of the Clause See e g Rayburn 497 F 3d at 660Jewish War Veterans 0fthe US ofAm v Gates 506 F Supp 2d 30 54 DDC 2007 Members cannot simply assert without more that the Speech or Debate Clause shields their activities and thereby preclude all further inquiry Yet that is precisely the treatment that the Executive requests here Similarly if the Executive s absolute immunity argument were to prevail Congress could be left with no recourse to obtain information that is plainly not subj ect to any colorable claim of executive privilege For instance surely at least 15 Id at 85 151 Id at 89 CRS33 some of the questions that the Committee intends to ask Ms Miers would not elicit a response subject to an assertion of privilege so too for responsive documents many of which may even have been produced already The Executive s proposed absolute immunity would thus deprive Congress of even nonprivileged information That is an unacceptable result152 On August 7 2008 the Justice Department noted its intent to appeal the ruling and requested that the court stay its order directing compliance with the subpoena until its appeal is resolved The district court s response to the stay request is pending The MiersBolten claim of executive privilege was the third of six such invocations by the Bush Administration 153 The first was asserted by President Bush on December 12 2001 directing Attorney General Ashcroftto refuse to comply with document subpoenas issued by the House Government Reform Committee as part of the investigation of alleged law enforcement corruption in the FBI s Boston Field Office over a period of almost 30 years Following two hearings in which the validity of the privilege claim was the central issue testimony presenting overwhelming evidence that similar DOJ documents and testimony had been provided in the face of investigative demands by jurisdictional committees for over 85 years despite claims of interference with prosecutorial deliberations and with a credible threat of a successful contempt vote on the oor of the House the documents were relinquished154 The second claim of privilege apparently asserted on behalf of the President by White House Counsel Alberto Gonzales occurred during the Judicial Watch litigation over the release of some 4300 pardon documents that were in the custody of the Pardon Attorney in the Justice Department and that had never been requested by White House officials or the President The panel majority heldthat in light of the Espy ruling the presidential communications privilege was inapplicable and ordered the documents to be released to the requesters The President has made three additional claims of executive privilege that are still unresolved155 One involves a continuation of the House Judiciary Committee s investigation of the removal and replacement of nine US Attorneys On July 10 2008 Karl Rove a former White House Deputy Chief of Staff refused to comply with a subpoena requiring his appearance for testimony before its Subcommittee on Commercial and Administrative Law claiming absolute immunity based on opinions and directions from the White House and the Department of Justice His claims of privilege were rejected by the Subcommittee On July 30 2008 the full Committee by a vote of 2014 approved a report recommending that Mr Rove be cited for 152 Id at 95 153 See Appendix 15quot See Everything Secret Degenerates The FBI s Use of Murderers and Informants HRept 108414 108d Cong 2nd Sess 121134 2004 See also CRS Report RL34197 Congressional Investigations of the Department of Justice 19202007 History Law and Practice by Morton Rosenberg 155 See Appendix CRS34 contempt by the House The recommendation has not yet been forwarded for oor action Privilege claims have been made by the President with respect to three subpoenas issued by the House Oversight and Government Reform Committee in April and May 2008 to the Administrator of the Environmental Protection Agency EPA and the Office of Information and Regulatory Affairs of the Office of Management and Budget OIRA The subpoena to OIRA and one of the subpoenas to the Administrator of EPA seek documents related to the EPA s promulgation of a regulation revising national ambient air quality standards for ozone on March 12 2008 The other subpoena directed to the EPA Administrator seeks documents re ecting communications between EPA and OIRA concerning the agency s decision to deny a petition by California for a waiver from federal preemption to enable it to regulate greenhouse gas emissions from motor vehicles The Attorney General on June 19 2008 advised the President that some 25 of the documents covered by the subpoena would be properly covered by an assertion of executive privilege On June 20 2008 the EPA Administrator advised the chairman of the Committee that he had been directed by the President to assert executive privilege with respect to the withheld documents No action has yet been taken by the Committee The most recent presidential privilege claim asserted on July 16 2008 at the behest of the Attorney General involves a House Oversight and Government Reform Committee subpoena to the Department of Justice DOJ for documents concerning DOJ s investigation by a Special Counsel concerning the disclosure of Valerie Plame Wilson s identity as an employee of the Central Intelligence Agency The documents sought and withheld include the FBI reports of the Special Counsel s interviews with the Vice President and senior White House staff handwritten notes taken by the Deputy National Security Advisor during conversations with the Vice President and senior White House officials and other documents provided by the White House during the course of the investigation The Attorney General s request to the President for a formal claim of privilege was spurred by the Committee s scheduling of a full Committee meeting to consider a resolution citing him for contempt of Congress156 Concluding Observations As indicated in the above discussion recent appellate court rulings cast considerable doubt on the broad claims of privilege posited by OLC in the past and now reiterated by the Clement Memo and the July 10 2007 OLC opinion on absolute witness immunity Taken together Espy and Judicial Watch arguably have effected important qualifications and restraints on the nature scope and reach of the presidential communications privilege As established by those cases and until reviewed by the Supreme Court the following elements appear to be essential to appropriately invoke the privilege 156 See letter to the Hon Henry A Waxman from Keith B Nelson Principal Deputy Assistant Attorney General Office of Legislative Affairs DOJ dated July 16 2008 attaching the Attorney General s request letter to the President dated July 15 2008 These letters are available from the author CRS35 l The protected communication must relate to a quintessential and non delegable presidential power Espy and Judicial Watch involved the appointment and removal and the pardon powers respectively Other core direct precedential decisionmaking powers include the Commanderin Chief power the sole authority to receive ambassadors and other public ministers and the power to negotiate treaties It would arguably not include decisionmaking with respect to laws that vest policymaking and administrative implementation authority in the heads of department and agencies or which allow presidential delegations of authority 2 The communication must be authored or solicited and received by a close White House advisor or the President The judicial test is that an advisor must be in operational proximity with the President This effectively means that the scope of the presidential communications privilege extends only to the administrative boundaries of the Executive Office of the President and the White House 3 The presidential communications privilege remains a quali ed privilege that may be overcome by a showing that the information sought likely contains important evidence and the unavailability of the information elsewhere by an appropriate investigating authority The Espy court found an adequate showing of need by the Independent Counsel while in Judicial Watch the court found the privilege did not apply and the deliberative process privilege was unavailing Definitively applying the teachings of Espy and Judicial Watch to current withholding claims in a context not yet fully developed may be premature However the recent district court ruling inMiers unequivocally rejecting the claim of absolute witness immunity and adopting the Committee s argument that Supreme Court s ruling in United States v Nixon allows only a qualified constitutional privilege that is presumptive when asserted but which may be overcome by a proper showing of need elsewhere by an authorized investigatory body such as a jurisdictional congressional committee and the court s further recognition that subsequent Supreme Court and appellate court rulings have reiterated the qualified nature of the privilege157 may be a clear indication that the Committee s position is on firm legal grounds It may be noted that the M iers opinion approvingly cited the Espy ruling five times with respect to doctrinal trends and interpretations concerning the presidential communications privilege further reinforcing the notion that Espy is the controlling law in the District of Columbia Circuit158 Also significant in the M iers opinion is the explicit rejection of the central legal position propounded by the Clement and OLC positions with respect to the claimed sufficiency of the nature and scope of the disclosures respecting the withheld documents that will be necessary to support the President s qualified privilege Ifthe initial Miers ruling is upheld on appeal the next phase of the litigation would directly confront the applicability and 157 d at 77 78 For an indepth discussion of the implications and importance of the court s justiciability rulings see CRS Report RL3 4097 Congress ContemptPower Law History Practice and Procedure by Morton Rosenberg and Todd B Tatelman 158 See Miers slip opinion at 323334 note 153485 note 35 and 88 note 37 CRS36 effect of Espy and Judicial Watch on the nature scope and reach of the presidential communications privilege CRS37 Appendix Presidential Claims of Executive Privilege From the Kennedy Administration Through the George W Bush Administration Following is a brief summary recounting of assertions of presidential claims of executive privilege from the Kennedy Administration through the George W Bush Administration 1 Kennedy President Kennedy established the policy that he and he alone would invoke the privilege Kennedy appears to have utilized the privilege twice with respect to information requests by congressional committees In 1962 the President directed the Secretary of Defense not to supply the names of individuals who wrote or edited speeches requested by a Senate subcommittee investigating military Cold War education and speech review policies The chairman of the subcommittee acquiesced to the assertion The President also directed that his military adviser General Maxwell Taylor refuse to testify before a congressional committee examining the Bay of Pigs affair See Rozell text note 1 at 4041 2 Johnson President Johnson although he announced that he would follow the Kennedy policy of personal assertion of executive privilege apparently did not do so in practice Rozell supra at 4142 catalogues three instances in which executive officials refused to comply with congressional committee requests for information or testimony which involved presidential actions but did not claim they were directed to do so by the President 3 Nixon President Nixon asserted executive privilege six times He directed Attorney General Mitchell to withhold FBI reports from a congressional committee in 1970 In 1971 Secretary of State Rogers asserted privilege at the President s direction to withhold information from Congress with respect to military assistance programs A claim of privilege was asserted at the direction of the President to prevent a White House advisor from testifying on the ITampT settlement during the Senate Judiciary Committee s consideration of the Richard Kleindienst nomination for Attorney General in 1972 Finally President Nixon claimed executive privilege three times with respect to subpoenas for White House tapes relating to the Watergate affair once with respect to a subpoena from the Senate Select Committee again with respect to a grand jury subpoena for the same tapes by Special Prosecutor Archibald Cox and then with respect to a jury trial subpoena for 64 additional tapes issued by Special Prosecutor Leon Jaworski Rozell supra at 5762 4 Ford and Carter President Ford directed Secretary State Kissinger to withhold documents during acongressional committee investigation relating to State Department recommendations to the National Security Council to conduct covert activities in 1975 President Carter directed Energy Secretary Duncan to claim executive privilege in the face of a committee s demand for documents relatingto the development and implementation of a policy to impose a petroleum import fee Rozell supra at 7782 8791 CRS38 5 Reagan President Reagan directed the assertion of executive privilege before congressional committees three times by Secretary of the Interior James Watt with respect to an investigation of Canadian oil leases 198182 by EPA Administrator Ann Burford with respect to Superfund enforcement practices 1982 83 and by Justice William Rehnquist during his nomination proceedings for Chief Justice with respect to memos he had written when he was Assistant Attorney for the Office of Legal Counsel in the Department of Justice 1986 Rozell supra at 98 105 6 Bush George H W President Bush asserted privilege only once in 1991 when he ordered Defense Secretary Cheney not to comply with a congressional subpoena for a document related to a subcommittee s investigation of cost overruns in and cancellation of a Navy aircraft program Rozell supra at 108119 7 Clinton President Clinton apparently discontinued the policy of issuing written directives to subordinate officials to exercise executive privilege Thus in some instances it is not totally clear when a claim of privilege by a subordinate was orally directed by the President even if it was shortly withdrawn The following documented assertions may arguably be deemed formal invocations Four of the assertions occurred during grand jury proceedings We list the individual assertions and brie y identify them i Kennedy Notes 1995executive privilege initially raised but never formally assertedSenate Whitewater investigation SRept 104 191 1043911 Cong 1St Sess 1995 ii White House Counsel Jack QuinnTravelgate investigations 1996House Government Reform HRept 104598 1043911 Cong 2d Sess 1996 iii FBIDEA Drug Enforcement Memo 1996House Judiciary iv Haiti Political Assassinations Documents 1996House Intemational Relations v In re Grand Jury Subpoena Duces Tecum 112 F 3d 910 83911 Cir 1997executive privilege claimed and then withdrawn in the district court Appeals court rejected applicability of common interest doctrine to communications with White House counsel s office attorneys and private attorneys for the First Lady vi Espy 121 F 3d 729 DC Cir 1997Espy caseexecutive privilege asserted but held overcome with respect to documents revealing false statements vii In re Grand Jury Proceedings 5 F Supp 2d 21 DDC 1998executive privilege claimed but held overcome because testimony of close advisors was relevant and necessary to grand jury investigation of Lewinski matter and was unavailable elsewhere The September 9 1998 Referral to the House of Representatives by Independent Counsel Kenneth Starr detailed the following previously undisclosed presidential claims of executive privilege viii xiii before grand juries that occurred during the Independent Counsel s investigations of the Hubbell and Lewinski matters CRS39 viii Thomas Mack McLarty 1997claimed at direction of President during Hubbell investigation but withdrawn prior to ling of a motion to compel ix Nancy Hemreich claimed at direction of President but withdrawn prior to March 20 1998 hearing to compel x Sidney Blumenthal claim rejected by District Court 5 F Supp 2d 21 DDC 1998 dropped on appeal xi Cheryl Mills claimed on August 11 1998 xii Lanny Breuer claimed on August 4 1998 and denied by Judge Johnson on August 11 In re Grand JuryProceeding Unpublished Order Under Seal August 11 1998 xiii Bruce Lindsey claimed on August 28 1998 H Doc 105310 105 11 Cong 2d Sess 206209 1998 xiv FALN Clemency claimed at direction of President by Deputy Counsel to the President Cheryl Mills on September 16 1999 in response to subpoenas by House Government Reform Committee 8 Bush George W President Bush has thus far asserted executive privilege six times once by written directive to the Attorney General and twice by apparent oral directives to subordinate executive of cials to claim the privilege i President Bush on December 12 2001 ordered Attorney General Ashcroft not to comply with a congressional subpoena for documents related to a House Committee s investigation of corruption in the FBI s Boston regional of ce The documents were ultimately released shortly after the conduct of the oversight hearings by the Committee HRept 108414 1083911 Cong 1St Sess 2004 ii Judicial Watch Inc v Department ofJustice 365 F 3d 1108 DC Cir 2004 Rejecting the claimed applicability of the presidential communications privilege to pardon documents sought under FOIA from DOJ s Of ce of the Pardon Attorney iii Removal and Replacement of U S Attorneys 2007 At the direction of the President on June 28 2007 the White House Counsel advised the House and Senate Judiciary Committees that subpoenas issuedfor documents and testimony relating to the ring of US Attorneys to former White House Counsel Harriet Miers and Chief of Staff Joshua B Bolten in 2006 were subject to a claim of executive privilege and that these present and former White House of cials would be ordered not to comply with either the document demands or to appear at a hearing Miers and Bolten were voted in contempt by the House on February 14 2008 and on February 28 the Speaker transmitted the contempt citation to the US Attorney for the District of Columbia for presentation to the grand jury The Attorney General directed the US Attorney not to present the citation On March 10 2008 the House Judiciary Committee initiated a civil suit seeking declaratory and injunctive relief to enforce the subpoenas Committee on the iv vi CRS40 Judiciary v Miers andBolten Case No 0800409 DDC On July 31 2008 the District Court ruled inter alia that The Executive s current claim of absolute immunity from compelled congressional process for senior precedential aides is without any support in the case law The court declared that Ms Miers is legally required to testify pursuant to a duly issued congressional subpoena and ordered Ms Miers and Mr Bolten to produce all subpoenaed non privileged documents and to provide speci c descriptions of all documents withheld on the basis fo executive privilege The Department of Justice led a notice of appeal to the DC Circuit on August 7 2008 and requested that the district court stay its order to testify and produce documents On April 9 and May 5 2008 the House Oversight and Government Reform Committee issued three subpoenas two to the Administrator of the Environmental Protection Agency EPA and one to the Office of Information and Regulatory Affairs of the Office of Management and Budget OIRA The subpoenato OIRA and one of the subpoenas to the Administrator of the EPA seek documents related to EPA s promulgation of regulations serving national ambient air quality standards for ozone on March 12 2008 The other subpoena directed to the EPA Administrator seeks documents reflecting communications between EPA and OIRA concerning the agency s decision to deny a petition by California for a waiver from federal preemption to enable te state to regulate greenhouse gas emissions from motor vehicles The Attorney General on June 19 2008 advised the President that some 25 of the documents covered bythe subpoena would be properly covered by an assertion of executive privilege On June 20 2008 the EPA Administrator advised the Chairman of the Committee that he had been directed by the President to assert executive privilege with respect to the withheld documents No action has yet been taken by the Committee Removal and Replacement of US Attorneys On July 10 2008 Karl Rove a former White House Deputy Chief of Staff refused to comply with a subpoena requiring his appearance before the House Judiciary Committee s Subcommittee on Commercial and Administrative Law claiming absolute immunity on the basis of White House and Department of Justice opinions and directions By a vote of 71 his claims of privilege were rejected by the Subcommittee On July 30 2008 the full Judiciary Committee by a vote of 20l4 approved a report recommending that Mr Rove be cited for contempt by the House The Judiciary Committee s recommendation has not yet been forwarded to the House for action Special Counsel s Investigation of Revelations of CIA Agent s Identity On July 16 2008 the President directed the Attorney General at the behest of the Attorney General to assert executive privilege with respect to a House Oversight and Government Reform Committee subpoena to the Department of Justice DOJ for CRS4l documents concerning DOJ s investigation by a Special Counsel concerning Valerie Plame Wilson s identity as an employee of the Central Intelligence Agency The documents sought and withheld include FBI reports of the Special Counsel s interviews with the Vice President and senior White House staff handwritten notes taken by the Deputy National Security Advisor during conversations with the Vice President and senior White House officials and other documents provided by the White House during the course of the investigation The Attorney General s request to the President for a formal claim of privilege was spurred bythe Committee s scheduling ofa meeting on July 16 2008 to consider a resolution citing him for contempt of Congress As of this date there has been no Committee response to the claim of privilege
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