FITS Headers
DIRBE_GPM_P3B.FITS
Primary Header
SIMPLE = T / file does conform to FITS standard BITPIX = 32 / number of bits per data pixel NAXIS = 0 / number of data axes EXTEND = T / FITS dataset may contain extensions COMMENT FITS (Flexible Image Transport System) format defined in Astronomy and COMMENT Astrophysics Supplement Series v44/p363, v44/p371, v73/p359, v73/p365. COMMENT Contact the NASA Science Office of Standards and Technology for the COMMENT FITS Definition document #100 and other FITS information. DATE = '11/02/97' / FITS file creation date (dd/mm/yy) DATE-MAP= '29/08/96' / Date of original data file creation (dd/mm/yy) ORIGIN = 'CDAC ' / Cosmology Data Analysis Center TELESCOP= 'COBE ' / Cosmic Background Explorer satellite INSTRUME= 'DIRBE ' / COBE instrument [DIRBE, DMR, FIRAS] OBJECT = 'GAL-SLICE' / part of sky given [e.g., ALL-SKY, WEEKLY-SKY, COMMENT / DAILY-SKY, GAL-SLICE, FACE ...] EQUINOX = 2000.0 / equinox of coords in following tables REFERENC= 'COBE/DIRBE Explanatory Supplement,' / REFERENC= 'ed. M.G. Hauser, T. Kelsall, D. Leisawitz, and J. Weiland,' / REFERENC= 'COBE Ref. Pub. No. 97-A (Greenbelt,MD: NASA/GSFC),' / REFERENC= 'available in electronic form from the NSSDC.' / COMMENT COMMENT COMMENT COBE specific keywords DATE-BEG= '01/01/90' / date of initial data represented (dd/mm/yy) DATE-END= '02/07/90' / date of final data represented (dd/mm/yy) PIXRESOL= 9 / Quad tree pixel resolution [6, 9] COMMENT COMMENT COMMENT DIRBE specific keywords PRODUCT = 'GPM ' / Galactic Plane Maps VERSION = 'Pass 3B ' / Version of Data Reduction Software WAVE1 = '1.25 microns' / nominal wavelength of Band 1 WAVE2 = '2.2 microns' / nominal wavelength of Band 2 WAVE3 = '3.5 microns' / nominal wavelength of Band 3 WAVE4 = '4.9 microns' / nominal wavelength of Band 4 WAVE5 = '12. microns' / nominal wavelength of Band 5 WAVE6 = '25. microns' / nominal wavelength of Band 6 WAVE7 = '60. microns' / nominal wavelength of Band 7 WAVE8 = '100. microns' / nominal wavelength of Band 8 WAVE9 = '140. microns' / nominal wavelength of Band 9 WAVE10 = '240. microns' / nominal wavelength of Band 10 SOLELONG= '90 degrees' / only solar elongations of 90 deg. represented APPVEC = 'COMBINED' / data having different approach vectors COMMENT / are combined during processing ZLREMOV = F / zodiacal foreground removal indicator COMMENT / if 'T(rue)', zodi foreground has been removed COMMENT / if 'F(alse)', observed sky brightness is given COMMENT COMMENT COMMENT COMMENT END
Extension Header 2
XTENSION= 'BINTABLE' / Extension type is Binary Table BITPIX = 8 / Binary data NAXIS = 2 / Data are in a table NAXIS1 = 80 / Number of 8 bit bytes in each row NAXIS2 = 73644 / Number of rows PCOUNT = 0 / Number of bytes of data following table GCOUNT = 1 / Group count (always 1 for bintable extensions) TFIELDS = 8 / Number of fields (columns) in the table COMMENT TIMVERSN= 'OGIP/93-003' / GSFC Ofice of Guest Investigator Programs (OGIP COMMENT / memo in which the convention is described COMMENT The times reported in this file are International COMMENT Atomic Time (TAI) seconds elapsed since COMMENT 00:00:00 UTC, 1 January 1981. Time information is COMMENT recorded in a manner consistent with the convention specified COMMENT in OGIP/93-003 with the understanding that time is counted COMMENT in atomic seconds and the origin of time (MJDREF) is quoted COMMENT in ephemeris MJD. TIMESYS = '1981.00 ' / time system (same as IRAS) MJDREFI = 44605 / Integer portion of ephemeris MJD COMMENT / corresponding to 0h UTC 1 Jan 1981 MJDREFF = 0.00059240741 / Fractional portion of ephemeris MJD COMMENT / corresponding to 0h UTC 1 Jan 1981 TIMEUNIT= 's ' / unit for TSTART, TSTOP, TIMEZERO = seconds TSTART = 283996977.572 / observation start time in TIMESYS system TSTOP = 299759964.990 / observation stop time in TIMESYS system COMMENT COMMENT COMMENT ------------------------------------------------------------------- COMMENT ******************************************************************* COMMENT Galactic-Plane Sky Maps -- COMMENT Photometric data for 10 bands (1.25 - 240 microns), COMMENT interpolated to a fixed solar elongation of 90 degrees COMMENT using Weekly-averaged sky maps as the basis for the COMMENT interpolation. COMMENT Array contains data only for pixels whose Galactic COMMENT coordinates satisfy the conditions: COMMENT -10 < b < +10 deg for 30 < l < 330 deg COMMENT -15 < b < +15 deg for 330 < l < 360 and 0 < l < 30 deg COMMENT ******************************************************************* COMMENT ------------------------------------------------------------------- COMMENT DIRBE Pixel number (resolution 9) TTYPE1 = 'Pixel_no' / pipeline fieldname = Pixel_no TUNIT1 = ' ' / TFORM1 = '1J ' / COMMENT ------------------------------------------------------------------- COMMENT Photometry COMMENT 10 intensities,in increasing band number COMMENT order (1A,2A,3A,4,5,6,7,8,9,10), COMMENT interpolated to solar elongation 90 deg. COMMENT The photometric measurements are given as COMMENT spectral intensities, I(nu) in MJy/sr, and COMMENT are quoted at the nominal wavelength COMMENT for a source with nu*I(nu) = constant -- i.e., COMMENT a color correction is required if the source COMMENT spectrum differs from nu*I(nu) = constant. COMMENT Data which have been replaced by flagged values COMMENT in processing have values .LE. -16375. TTYPE2 = 'Photomet' / pipeline fieldname = Photometry TUNIT2 = 'MJy/sr ' / MegaJanskys/steradian TFORM2 = '10E ' / TDIM2 = '(10) ' / COMMENT ------------------------------------------------------------------- COMMENT Data quality flag COMMENT Indicates quality of interpolation to elongation = 90 deg. COMMENT for each photometric measure. COMMENT Listed in increasing band number order: (1A,2A,3A,4,5,6,7,8,9,10) COMMENT COMMENT COMMENT Byte 1 (least significant byte): COMMENT Bit 0 = least significant bit COMMENT Bits 0-3: Indicator for input data COMMENT quality and interpolation quality: COMMENT 0001: One or more weekly average(s) COMMENT had some data removed due to solar COMMENT system object contamination. COMMENT 0010: Only two points (weekly averages) COMMENT available for the interpolation. Expect COMMENT systematic error. COMMENT 0100: Average value used rather than interpolated COMMENT value, for quality reasons. COMMENT 1111: Interpolation impossible. Photometry set COMMENT to a flagged value (.LE. -16375.) COMMENT COMMENT COMMENT Bits 4-7: Interpolation type indicator: COMMENT 0000: Interpolation COMMENT 0001: Extrapolation from above COMMENT ( > specified elongation) COMMENT 0010: Extrapolation from below COMMENT ( < specified elongation) COMMENT 0100: One weekly average was flagged COMMENT as an outlier and not used in COMMENT the interpolation process. COMMENT COMMENT COMMENT Byte 2 (most significant byte): COMMENT Relative or absolute standard deviation COMMENT on the interpolated/extrapolated COMMENT intensity for each band, given in COMMENT logarithmic binning. COMMENT Units = none (Bands 1 - 8) COMMENT = MJy/sr (Bands 9 and 10) COMMENT Range = [0,255] COMMENT The byte value B has been found from the COMMENT RELATIVE standard deviation R = sigma(I)/ABS(I) (Bands 1 to 8) COMMENT or ABSOLUTE standard deviation R = sigma(I) (Bands 9 and 10) COMMENT as follows: COMMENT N = 3: Bands 1 - 4, 7 and 8 COMMENT N = 4: Bands 5 and 6 COMMENT N = 1: Bands 9 and 10 COMMENT COMMENT if R <= 10**-N then B = 0 COMMENT if 10**-N < R < 10**(-N+4) then B = IFIX((N+log10(R))*254./4.)+1 COMMENT if R >= 10**(-N+4) then B = 255 COMMENT COMMENT COMMENT Conversely, the sigma value can be reconstructed by: COMMENT R <= 10**-N if B = 0 COMMENT R = 10**(4*(B-0.5)/254. - N) if 1 <= B <= 254 COMMENT R >= 10**(-N+4) if B = 255 COMMENT COMMENT COMMENT sigma = R * ABS(I) (Bands 1 - 8) COMMENT sigma = R (Bands 9 and 10) COMMENT (The maximum error on the reconstructed value is 1.8 %) TTYPE3 = 'PhotQual' / pipeline fieldname = Phot_quality TUNIT3 = ' ' / TFORM3 = '10I ' / TDIM3 = '(10) ' / COMMENT ------------------------------------------------------------------- COMMENT Time in International Atomic Time (TAI) seconds COMMENT elapsed since 1-JAN-1981:00:00:00.000 UTC. COMMENT Computed time corresponding to observation COMMENT of pixel at solar elongation = 90 deg. TTYPE4 = 'TIME ' / pipeline fieldname = Time TUNIT4 = 's ' / TFORM4 = '1D ' / COMMENT ------------------------------------------------------------------- COMMENT Ecliptic longitude of pixel center COMMENT range = [0,360) degrees TTYPE5 = 'EcLon ' / pipeline fieldname = Ecliptic_longitude TUNIT5 = 'deg ' / TFORM5 = '1I ' / TSCAL5 = 0.0109867 / bin size 360/(2**15-1) degrees TZERO5 = 0.00549333 / offset to bin center in degrees COMMENT ------------------------------------------------------------------- COMMENT Ecliptic latitude of pixel center COMMENT range = [-90, 90] degrees TTYPE6 = 'EcLat ' / pipeline fieldname = Ecliptic_latitude TUNIT6 = 'deg ' / TFORM6 = '1I ' / TSCAL6 = 0.0109867 / bin size 360/(2**15-1) degrees TZERO6 = 0.00549333 / offset to bin center in degrees COMMENT ------------------------------------------------------------------- COMMENT Galactic longitude of pixel center COMMENT range = [0,360) degrees TTYPE7 = 'GaLon ' / pipeline fieldname = Galactic_longitude TUNIT7 = 'deg ' / TFORM7 = '1I ' / TSCAL7 = 0.0109867 / bin size 360/(2**15-1) degrees TZERO7 = 0.00549333 / offset to bin center in degrees COMMENT ------------------------------------------------------------------- COMMENT Galactic latitude of pixel center COMMENT range = [-90, 90] degrees TTYPE8 = 'GaLat ' / pipeline fieldname = Galactic_latitude TUNIT8 = 'deg ' / TFORM8 = '1I ' / TSCAL8 = 0.0109867 / bin size 360/(2**15-1) degrees TZERO8 = 0.00549333 / offset to bin center in degrees COMMENT ------------------------------------------------------------------- END
