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Example 6: DIRBE FITS Headers

(The first two lines following are provided to help the reader determine column numbers. They are not part of FITS headers.)

00000000011111111111222222222233333333333444444444455555555556666666666777
12345678901234567890123456789012345678901234567890123456789012345678909012

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            
DATE    = '28/09/94'           / FITS file creation date (dd/mm/yy)             
DATE-MAP= '10/07/94'           / Date of original 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  = 'ALL-SKY '           / part of sky given [ALL-SKY, WEEKLY-SKY,      
COMMENT                        /                    GAL-SLICE]                  
EQUINOX =               2000.0 / equinox of coords in following tables          
REFERENC= 'DIRBE Explanatory Supplement' /                                      
COMMENT     COBE specific keywords                                              
DATE-BEG= '11/12/89'           / date of initial data represented (dd/mm/yy)    
DATE-END= '21/09/90'           / date of final data represented   (dd/mm/yy)    
PIXRESOL=                    9 / Quad tree pixel resolution [6, 9]              
COMMENT                                                                         
COMMENT     DIRBE specific keywords                                             
PRODUCT = 'B09_AAM '           / Band 9 Annual Average Sky Map                 
VERSION = 'Pass 2B '           / Version of Data Reduction Software             
WAVE9   = '140. microns'       / nominal wavelength of Band 9                   
SOLELONG= 'ALL     '           / all available solar elongations included       
APPVEC  = 'COMBINED'           / approach vectors combined                      
ZLREMOV = 'NO      '           / signal from zodiacal dust remains in map       
COMMENT                                                                         
COMMENT                                                                         
END

(8 card images of ASCII blanks)

XTENSION= 'BINTABLE'           / Extension type is Binary Table                 
BITPIX  =                    8 / Binary data                                    
NAXIS   =                    2 / Data are in a table                            
NAXIS1  =                   27 / Number of 8 bit bytes in each row              
NAXIS2  =               393216 / Number of rows                                 
PCOUNT  =                    0 / Number of bytes of data following table        
GCOUNT  =                    1 / Group count (always 1 for bintable extensions) 
TFIELDS =                    7 / 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  =        282185275.611 / observation start time in TIMESYS system  
TSTOP   =        306753235.358 / observation stop time in TIMESYS system   
COMMENT                                                                         
COMMENT   -------------------------------------------------------------------   
COMMENT   *******************************************************************   
COMMENT          Annual Average Sky Map -- 140. microns                         
COMMENT          Mission-averaged photometric measurements and cumulative 
COMMENT          sky coverage data for DIRBE Band 9 (140. microns).           
COMMENT          The photometry is computed from the weighted average of all 
COMMENT          available weekly-averaged maps for the entire mission,        
COMMENT          up to the time when the cryogen supply was exhausted.       
COMMENT          The foreground signal from Zodiacal dust remains in the map.
COMMENT   *******************************************************************   
COMMENT   -------------------------------------------------------------------   
COMMENT   ====================================================================
COMMENT   Coordinate Information (Spatial and Temporal):                        
COMMENT   ===================================================================
COMMENT   -------------------------------------------------------------------   
COMMENT       DIRBE Pixel number (resolution 9)                                 
TTYPE1  = 'Pixel_no'           / entire fieldname = Pixel_no                    
TUNIT1  = '        '           /                                                
TFORM1  = '1J      '           /                                                
COMMENT   --------------------------------------------------------------------- 
COMMENT        Sub-pixel containing the mean DIRBE LOS (line-of-sight)       
COMMENT         when pixel is divided into 256                                  
COMMENT         sub-pixels (16x16 grid) according to                            
COMMENT         standard quad-sphere rules.                                     
TTYPE2  = 'PSubPos '           / entire fieldname = Pixel_subpos                
TUNIT2  = '        '           /                                                
TFORM2  = '1B      '           /                                                
COMMENT   --------------------------------------------------------------------  
COMMENT       Time in TAI seconds since 01-JAN-1981:00:00:00.000 UTC.    
COMMENT       This is the average time of all observations of a pixel           
COMMENT       within the time interval TSTART to TSTOP,                         
COMMENT       regardless of the weight assigned to a particular observation.  
COMMENT       For this product, not a physically meaningful quantity.           
TTYPE3  = 'Time    '           / entire fieldname = Time                        
TUNIT3  = '        '           /                                                
TFORM3  = '1D      '           /                                                
COMMENT   -------------------------------------------------------------------   
COMMENT   ===================================================================   
COMMENT   DIRBE Sky Brightness Information:                                     
COMMENT   ===================================================================   
COMMENT   -------------------------------------------------------------------   
COMMENT       Cumulative weighted average of the 140. micron photometry.  
COMMENT        This average is calculated using the weighted number of        
COMMENT        observations from each Weekly Averaged Map ( WtNumObs from       
COMMENT        the Weekly Averaged Map) as the weight, such that                
COMMENT        annual_average =                                                 
COMMENT           sum( weekly_average * weekly_weight )/ sum( weekly_weight)   
COMMENT                                                                         
COMMENT        The photometric measurement is given as a                        
COMMENT        spectral intensity, I(nu) in MJy/sr, and                         
COMMENT        is 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.                           
COMMENT                                                                         
TTYPE4  = 'Photomet'           / entire fieldname = Photometry                  
TUNIT4  = 'MJy/sr  '           /                                                
TFORM4  = '1E      '           /                                                
COMMENT   --------------------------------------------------------------------  
COMMENT        The standard deviation of the (weighted) average photometry 
COMMENT         values.                                                         
TTYPE5  = 'StdDev  '           / entire fieldname = Standard_deviation          
TUNIT5  = 'MJy/sr  '           /                                                
TFORM5  = '1E      '           /                                                
COMMENT   --------------------------------------------------------------------  
COMMENT        Sum of the weekly weighted number of observations that went into 
COMMENT         forming the annual averages.                                    
TTYPE6  = 'WtNumObs'           / entire fieldname = Weighted_num_obs          
TUNIT6  = '        '           /                                                
TFORM6  = '1I      '           /                                                
COMMENT   --------------------------------------------------------------------- 
COMMENT        Sum of the total number of observations available, regardless 
COMMENT         of assigned weight.                                             
TTYPE7  = 'SumNRecs'           / entire fieldname = Sum_numrecs                 
TUNIT7  = '        '           /                                                
TFORM7  = '1J      '           /                                                
COMMENT   --------------------------------------------------------------------- 
END
(20 card images of ASCII blanks)