SIMPLE  =                    T / file does conform to FITS standard
BITPIX  =                    8 / 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 is defined in 'Astronomy
COMMENT   and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
HDRVER  = '3.4             '   / Header version 
FITSTYPE= 'PSRFITS '           / FITS definition for pulsar data files
DATE    = '                '   / File creation date (YYYY-MM-DDThh:mm:ss UTC)
OBSERVER= '                '   / Observer name(s)
PROJID  = 'ARTSSC          '   / Project name
TELESCOP= 'WSRT    '           / Telescope name
ANT_X   =  3828445.659         / [m] Antenna ITRF X-coordinate (D)
ANT_Y   =  445223.600          / [m] Antenna ITRF Y-coordinate (D)
ANT_Z   =  5064921.5677        / [m] Antenna ITRF Z-coordinate (D)
FRONTEND= 'APERTIF '           / Rx and feed ID
NRCVR   = 2                    / Number of receiver polarisation channels
FD_POLN = 'LIN     '           / LIN or CIRC
FD_HAND = -1                   / +/- 1. +1 is LIN:A=X,B=Y, CIRC:A=L,B=R (I)
FD_SANG = 45.0                 / [deg] FA of E vect for equal sig in A&B (E)
FD_XYPH = 0.0                  / [deg] Phase of A^* B for injected cal (E)
BACKEND = 'ARTS    '           / Backend ID
BECONFIG= 'SC      '           / Backend configuration file name
BE_PHASE= -1                   / 0/+1/-1 BE cross-phase:0 unknown,+/-1 std/rev
BE_DCC  = 0                    / 0/1 BE downconversion conjugation corrected
BE_DELAY= 0.0                  / [s] Backend propn delay from digitiser input 
TCYCLE  = 0.0                  / [s] On-line cycle time (D)
OBS_MODE= 'SEARCH  '           / (PSR, CAL, SEARCH)
DATE-OBS= '2017-10-31T15:08:00' / Date of observation (YYYY-MM-DDThh:mm:ss UTC)
OBSFREQ = 1400                 / [MHz] Centre frequency for observation
OBSBW   = 300                  / [MHz] Bandwidth for observation
OBSNCHAN= 1536                 / Number of frequency channels (original)
CHAN_DM =                   0. / DM used to de-disperse each channel (pc/cm^3)
SRC_NAME= '                '   / Source or scan ID 
COORD_MD= 'J2000   '           / Coordinate mode (J2000, GAL, ECLIP, etc.)
EQUINOX = 2000.0               / Equinox of coords (e.g. 2000.0) 
RA      = '00:00:00.0000   '   / Right ascension (hh:mm:ss.ssss)
DEC     = '-00:00:00.000   '   / Declination (-dd:mm:ss.sss)
BMAJ    =                  1.  / [deg] Beam major axis length
BMIN    =                  1.  / [deg] Beam minor axis length
BPA     = 0.0                  / [deg] Beam position angle
STT_CRD1= '                '   / Start coord 1 (hh:mm:ss.sss or ddd.ddd)
STT_CRD2= '                '   / Start coord 2 (-dd:mm:ss.sss or -dd.ddd) 
TRK_MODE= 'TRACK   '           / Track mode (TRACK, SCANGC, SCANLAT)
STP_CRD1= '                '   / Stop coord 1 (hh:mm:ss.sss or ddd.ddd)
STP_CRD2= '                '   / Stop coord 2 (-dd:mm:ss.sss or -dd.ddd) 
SCANLEN =               28800. / [s] Requested scan length (E)
FD_MODE = 'FA      '           / Feed track mode - FA, CPA, SPA, TPA
FA_REQ  = 0.0                  / [deg] Feed/Posn angle requested (E)
CAL_MODE= 'OFF     '           / Cal mode (OFF, SYNC, EXT1, EXT2)
CAL_FREQ= 0.0                  / [Hz] Cal modulation frequency (E)
CAL_DCYC= 0.0                  / Cal duty cycle (E)
CAL_PHS = 0.0                  / Cal phase (wrt start time) (E)
STT_IMJD=                57483 / Start MJD (UTC days) (J - long integer)
STT_SMJD=                18780 / [s] Start time (sec past UTC 00h) (J)
STT_OFFS= 2.37487256526947E-07 / [s] Start time offset (D)   
STT_LST =     14469.1542386173 / [s] Start LST (D)
END
XTENSION = 'BINTABLE'         /  ***** Subintegration data *****
BITPIX = 8                    / N/A
NAXIS = 2                     / 2-dimensional binary table
NAXIS1 = 76861516             / width of table in bytes
NAXIS2 = 0                    / Number of rows in table (NSUBINT)
PCOUNT = 0                    / size of special data area
GCOUNT = 1                    / one data group (required keyword)
TFIELDS = 17                  / Number of fields per row
INT_TYPE = 'TIME '            / Time axis (TIME, BINPHSPERI, BINLNGASC, etc)
INT_UNIT = 'SEC '             / Unit of time axis (SEC, PHS (0-1), DEG)
SCALE = 'FluxDen '            / Intensity units (FluxDen/RefFlux/Jansky)
NPOL = 4                      / Number of polarisations
POL_TYPE = 'IQUV  '           / Polarisation identifier (e.g., AABBCRCI, AA+BB)
TBIN = 8.192E-5               / [s] Time per bin or sample This is wall time not integration time.
NBIN = 1                      / Nr of bins (PSR/CAL mode; else 1)
NBIN_PRD = 0                  / Nr of bins/pulse period (for gated data)
PHS_OFFS = 0.                 / Phase offset of bin 0 for gated data
NBITS = 8                     / Nr of bits/datum (SEARCH mode 'X' data, else 1)
ZERO_OFF = 0.                 / Zero offset for SEARCH mode data when using unsigned data
SIGNINT = 0                   / Unsigned integers
NSUBOFFS = 0                  / Subint offset (Contiguous SEARCH-mode files)
NCHAN = 1536                  / Number of channels/sub-bands in this file
CHAN_BW = -0.1953125          / [MHz] Channel/sub-band width < 0 --> band is flipped in frequency
NCHNOFFS = 0                  / Channel/sub-band offset for split files
NSBLK = 12500                 / Samples/row (SEARCH mode, else 1)
EXTNAME = 'SUBINT '           / name of this binary table extension
TTYPE1  = TSUBINT             / Length of subintegration
TFORM1  = 1D                  / Double 
TTYPE2  = OFFS_SUB            / Offset from Start of subint centre
TFORM2  = 1D                  / Double 
TTYPE3  = LST_SUB             / LST at subint centre 
TFORM3  = 1D                  / Double 
TTYPE4  = RA_SUB              / RA (J2000) at subint centre
TFORM4  = 1D                  / Double 
TTYPE5  = DEC_SUB             / Dec (J2000) at subint centre
TFORM5  = 1D                  / Double 
TTYPE6  = GLON_SUB            / [deg] Gal longitude at subint centre
TFORM6  = 1D                  / Double 
TTYPE7  = GLAT_SUB            / [deg] Gal latitude at subint centre
TFORM7  = 1D                  / Double 
TTYPE8  = FD_ANG              / [deg] Feed angle at subint centre
TFORM8  = 1E                  / Float
TTYPE9  = POS_ANG             / [deg] Position angle of feed at subint centre
TFORM9  = 1E                  / Float
TTYPE10 = PAR_ANG             / [deg] Parallactic angle at subint centre
TFORM10 = 1E                  / Float
TTYPE11 = TEL_AZ              / [deg] Telescope azimuth at subint centre
TFORM11 = 1E                  / Float 
TTYPE12 = TEL_ZEN             / [deg] Telescope zenith angle at subint centre
TFORM12 = 1E                  / Float
TTYPE13 = DAT_FREQ            / [MHz] Centre frequency for each channel
TFORM13 = 1536E               / NCHAN floats
TTYPE14 = DAT_WTS             / Weights for each channel
TFORM14 = 1536E               / NCHAN floats
TTYPE15 = DAT_OFFS            / Data offset for each channel
TFORM15 = 6144E               / NCHAN*NPOL floats
TTYPE16 = DAT_SCL             / Data scale factor for each channel
TFORM16 = 6144E               / NCHAN*NPOL floats
TTYPE17 = 'DATA    '          / Subint data table uses field keyword DATA
TDIM17 = '(1,1536,4,12500)'   / dataAr Dimensions (NBIN,NCHAN,NPOL,NSBLK)
TFORM17 = '76800000B'         / NBIN*NCHAN*NPOL*NSBLK I(short), B(byte) or X(bit)
TUNIT1  = s                   / Units of field
TUNIT2  = s                   / Units of field
TUNIT3  = s                   / Units of field
TUNIT4  = deg                 / Units of field
TUNIT5  = deg                 / Units of field
TUNIT6  = deg                 / Units of field
TUNIT7  = deg                 / Units of field
TUNIT8  = deg                 / Units of field
TUNIT9  = deg                 / Units of field
TUNIT10 = s                   / Units of field
TUNIT11 = deg                 / Units of field
TUNIT12 = deg                 / Units of field
TUNIT13 = deg                 / Units of field
TUNIT17 = Jy                  / Units of subint data
END
