FITS Headers
FIRAS_DIFFERENTIAL_SKY_SPECTRA_LLFS.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 = '30/07/97' / FITS file creation date (dd/mm/yy) ORIGIN = 'CDAC ' / Cosmology Data Analysis Center TELESCOP= 'COBE ' / COsmic Background Explorer satellite INSTRUME= 'FIRAS ' / COBE instrument [DIRBE, DMR, FIRAS] OBJECT = 'ALL-SKY ' / part of sky given [ALL-SKY, GAL-SLICE] PRODUCT = 'SKY-DIFF' / Differential sky spectra EQUINOX = 2000.0 / equinox of coords in following tables COMMENT REFERENC= 'For additional information, please refer to the' / REFERENC= 'COBE Far Infrared Absolute Spectrophotometer (FIRAS)' / REFERENC= 'Explanatory Supplement, ed. J.C. Mather et al,' / REFERENC= 'COBE Ref. Pub. No. 97-C (Greenbelt, MD: NASA/GSFC),' / REFERENC= 'available in electronic form from the NSSDC.' / COMMENT COMMENT COBE specific keywords DATE-BEG= '24/11/89' / date of initial data represented (dd/mm/yy) DATE-END= '21/09/90' / date of final data represented (dd/mm/yy) PIXRESOL= 6 / Quad tree pixel resolution [6, 9] COMMENT COMMENT FIRAS specific keywords CHANSCAN= 'LLFS ' / Channel and mirror transport mechanism scan COMMENT / mode identifier. The first two characters COMMENT / indicate the channel, the first being the COMMENT / instrument side: right (R) or left (L); and COMMENT / the second being the frequency: high (H) or COMMENT / low (L). The third and fourth characters COMMENT / indicate the scan mode, the third being the COMMENT / scan length: short (S) or long (L); and the COMMENT / fourth being the scan speed: slow (S) or COMMENT / fast (F). In addition, the scan mode may COMMENT / take the following values for low frequency COMMENT / data only (channel = RL or LL): COMMENT / FS: decimated SF data; COMMENT / FL: truncated LF data. MODLLABL= 'PASS4 ' / FIRAS calibration model solution label MISS_SEG= 'ENTIRE_MISSION' / FIRAS segment of mission represented NU_ZERO = 68.020812 / Optical frequency of initial data point in GHz DELTA_NU= 13.604162 / Optical frequency interval between data points COMMENT / in GHz NUM_FREQ= 43 / Number of frequency points with good data FFT_LENG= 160 / Length of Fast Fourier Transform used END
Extension Header 2
XTENSION= 'BINTABLE' / Extension type is Binary Table BITPIX = 8 / Binary data NAXIS = 2 / Data are in a table NAXIS1 = 4234 / Number of 8 bit bytes in each row NAXIS2 = 5048 / Number of rows PCOUNT = 0 / Number of bytes of data following table GCOUNT = 1 / Group count (always 1 for bintable extensions) TFIELDS = 35 / Number of fields (columns) in the table COMMENT TIMVERSN= 'OGIP/93-003' / OGIP memo number where the convention COMMENT / is described COMMENT The times reported in this file are atomic seconds elapsed COMMENT since 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 = 280713605.000 / observation start time in TIMESYS system TSTOP = 306806405.990 / observation stop time in TIMESYS system COMMENT COMMENT COMMENT FIRAS Spectrum COMMENT Project Dataset Record Structure COMMENT COMMENT COMMENT Instrument Attitude Information COMMENT COMMENT FIRAS pixel number (resolution 6) TFORM1 = '1J ' / TTYPE1 = 'PIXEL ' / entire fieldname = PIXEL TUNIT1 = ' ' / COMMENT Galactic longitude, in deg (0 -> 360) TFORM2 = '1E ' / TTYPE2 = 'GAL_LON ' / entire fieldname = GAL_LON TUNIT2 = 'deg ' / COMMENT Galactic latitude, in deg (-90 -> +90) TFORM3 = '1E ' / TTYPE3 = 'GAL_LAT ' / entire fieldname = GAL_LAT TUNIT3 = 'deg ' / COMMENT Ecliptic longitude, epoch 2000.0, in deg (0 -> 360) TFORM4 = '1E ' / TTYPE4 = 'ECL_LON ' / entire fieldname = ECL_LON TUNIT4 = 'deg ' / COMMENT Ecliptic latitude, epoch 2000.0, in deg (-90 -> +90) TFORM5 = '1E ' / TTYPE5 = 'ECL_LAT ' / entire fieldname = ECL_LAT TUNIT5 = 'deg ' / COMMENT Right ascension, in deg (0 -> 360) TFORM6 = '1E ' / TTYPE6 = 'RA ' / entire fieldname = RA TUNIT6 = 'deg ' / COMMENT Declination, in deg (-90 -> +90) TFORM7 = '1E ' / TTYPE7 = 'DEC ' / entire fieldname = DEC TUNIT7 = 'deg ' / COMMENT COMMENT Spectrum and Sigmas COMMENT COMMENT Real part of spectrum, in MJy/sr TFORM8 = '210E ' / TDIM8 = '(210) ' / TTYPE8 = 'REAL_SPE' / entire fieldname = REAL_SPECTRUM TUNIT8 = 'MJy/sr ' / COMMENT Imaginary part of spectrum, in MJy/sr TFORM9 = '210E ' / TDIM9 = '(210) ' / TTYPE9 = 'IMAG_SPE' / entire fieldname = IMAG_SPECTRUM TUNIT9 = 'MJy/sr ' / COMMENT Sigmas of spectrum, in MJy/sr TFORM10 = '210E ' / TDIM10 = '(210) ' / TTYPE10 = 'SIGMAS ' / entire fieldname = SIGMAS TUNIT10 = 'MJy/sr ' / COMMENT COMMENT Number and Times of IFGs COMMENT COMMENT Number of IFGs in spectrum TFORM11 = '1J ' / TTYPE11 = 'NUM_IFGS' / entire fieldname = NUM_IFGS TUNIT11 = ' ' / COMMENT Glitch rate for spectrum, in glitches/s TFORM12 = '1E ' / TTYPE12 = 'GLITCH_R' / entire fieldname = GLITCH_RATE TUNIT12 = 'gl/s ' / COMMENT Glitch rate weighted number of IFGs in spectrum TFORM13 = '1E ' / TTYPE13 = 'ADJ_NUM_' / entire fieldname = ADJ_NUM_IFGS TUNIT13 = ' ' / COMMENT Average data collection time in seconds since COMMENT 00:00.00 UTC, 1 January 1981 TFORM14 = '1D ' / TTYPE14 = 'TIME ' / entire fieldname = TIME TUNIT14 = 's ' / COMMENT Observation times of IFGs in the spectrum; COMMENT in hundredths of days since ejection of the COMMENT FIRAS aperture cover at COMMENT 11:18.00 UTC, 21 November 1989 TFORM15 = '100J ' / TDIM15 = '(100) ' / TTYPE15 = 'IFG_TIME' / entire fieldname = IFG_TIMES TUNIT15 = 'd*100 ' / COMMENT Flag indicating orphan IFGs, which occur COMMENT when a spectrum is composed of only 1 or COMMENT 2 IFGs. In all other cases, the spectrum COMMENT is composed of three or more IFGs; COMMENT applicable only to sky data. COMMENT Flag = 1 indicates 1 or 2 IFGS in the spectrum; COMMENT flag = 0 indicates 3 or more IFGs in the spectrum. TFORM16 = '1B ' / TTYPE16 = 'ORPHANS ' / entire fieldname = ORPHANS TUNIT16 = ' ' / COMMENT COMMENT Template Information COMMENT COMMENT Number of templates subtracted from spectrum TFORM17 = '1J ' / TTYPE17 = 'NUM_TEMP' / entire fieldname = NUM_TEMPLATES TUNIT17 = ' ' / COMMENT Number of IFGS used in forming the templates TFORM18 = '1J ' / TTYPE18 = 'TPL_NUM_' / entire fieldname = TPL_NUM_IFGS TUNIT18 = ' ' / COMMENT Flag indicating use of IFGs from neighboring COMMENT pixels in template formation (suitable COMMENT IFGs from 8 neighboring pixels); COMMENT applicable only to sky data. COMMENT Flag = 1 indicates neighbor IFGs were used; COMMENT flag = 0 indicates neighbor IFGs were not used. TFORM19 = '1B ' / TTYPE19 = 'NEIGHBOR' / entire fieldname = NEIGHBORS TUNIT19 = ' ' / COMMENT Number of IFGS from neighboring pixels used in COMMENT forming the templates; only for sky data TFORM20 = '1J ' / TTYPE20 = 'NBR_NUM_' / entire fieldname = NBR_NUM_IFGS TUNIT20 = ' ' / COMMENT Observation times of IFGs used in template COMMENT formation; in seconds since COMMENT 00:00.00 UTC, 1 January 1981 TFORM21 = '100D ' / TDIM21 = '(100) ' / TTYPE21 = 'TPL_TIME' / entire fieldname = TPL_TIMES TUNIT21 = 's ' / COMMENT Pixel numbers of IFGs used in templates TFORM22 = '100J ' / TDIM22 = '(100) ' / TTYPE22 = 'TPL_PIXE' / entire fieldname = TPL_PIXELS TUNIT22 = ' ' / COMMENT COMMENT Bolometer Response Function COMMENT COMMENT Commanded bolometer bias, in V TFORM23 = '1E ' / TTYPE23 = 'BOLOM_BI' / entire fieldname = BOLOM_BIAS TUNIT23 = 'V ' / COMMENT Bolometer readout voltage, in V TFORM24 = '1E ' / TTYPE24 = 'BOLOM_VO' / entire fieldname = BOLOM_VOLTAGE TUNIT24 = 'V ' / COMMENT Bolometer DC response, in V/W TFORM25 = '1E ' / TTYPE25 = 'DC_RESPO' / entire fieldname = DC_RESPONSE TUNIT25 = 'V/W ' / COMMENT Bolometer time constant, in s TFORM26 = '1E ' / TTYPE26 = 'TIME_CON' / entire fieldname = TIME_CONSTANT TUNIT26 = 's ' / COMMENT Linear autophase correction, in rad TFORM27 = '1E ' / TTYPE27 = 'PHASE_CO' / entire fieldname = PHASE_CORR TUNIT27 = 'rad ' / COMMENT COMMENT Instrument Temperatures COMMENT COMMENT External calibrator temperature, in K TFORM28 = '1E ' / TTYPE28 = 'XCAL_TEM' / entire fieldname = XCAL_TEMP TUNIT28 = 'K ' / COMMENT Internal calibrator temperature, in K TFORM29 = '1E ' / TTYPE29 = 'ICAL_TEM' / entire fieldname = ICAL_TEMP TUNIT29 = 'K ' / COMMENT Sky horn temperature, in K TFORM30 = '1E ' / TTYPE30 = 'SKYHORN_' / entire fieldname = SKYHORN_TEMP TUNIT30 = 'K ' / COMMENT Reference horn temperature, in K TFORM31 = '1E ' / TTYPE31 = 'REFHORN_' / entire fieldname = REFHORN_TEMP TUNIT31 = 'K ' / COMMENT Dihedral mirror temperature, in K TFORM32 = '1E ' / TTYPE32 = 'DIHEDRAL' / entire fieldname = DIHEDRAL_TEMP TUNIT32 = 'K ' / COMMENT Collimator mirror temperature, in K TFORM33 = '1E ' / TTYPE33 = 'MIRROR_T' / entire fieldname = MIRROR_TEMP TUNIT33 = 'K ' / COMMENT Bolometer operating temperature, in K TFORM34 = '1E ' / TTYPE34 = 'BOLOM_TE' / entire fieldname = BOLOM_TEMP TUNIT34 = 'K ' / COMMENT Bolometer bath temperature, in K TFORM35 = '1E ' / TTYPE35 = 'BATH_TEM' / entire fieldname = BATH_TEMP TUNIT35 = 'K ' / COMMENT END
