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Sample header info




Folks,

I think that it would be a mistake to not include easily
computable information like airmass and heliocentric JD in the 
header at the time of image creation. This removes an inevitable 
impediment to progress later on. I also think that it *is* a
good idea to record the steps of how the image has been mutilated.

Here is a FITS header from a WIYN image I took a few years back
for reference. It is overkill, to be sure, but it does illustrate
what others have done. (I would have added HJD, as well).

Cheers,
Doug


dcd0009.imh[2043,2042][real]: M13 B 15sec
No bad pixels, min=unknown, max=unknown
Line storage mode, physdim [2048,2042], length of user area 2512 s.u.
Created Mon 16:03:34 08-Mar-1999, Last modified Mon 16:03:34 08-Mar-1999
Pixel file "HDR$dcd0009.pix" [ok]
'KPNO-IRAF'           /
'15-07-97'            /
New copy of dcd0009.imh
IRAF-MAX=           0.000000E0  /  DATA MAX
IRAF-MIN=           0.000000E0  /  DATA MIN
IRAF-BPX=                   32  /  DATA BITS/PIXEL
IRAFTYPE= 'REAL    '            /  PIXEL TYPE
HDR_REV = '1.010  13Jul94     (title @ end of pic; UTSHUT)' /
ORIGPIC = 'obj0371'            / Original picture file name
OPICNUM =                  371 / Original picture number
NAMPSYX = '1 1'                / Num amps in y & x (eg. '2 2'=quad)
AMPLIST = '11'                 / Readout order in y,x
OBSERVAT= 'KPNO'               / Origin of data
TELESCOP= 'WIYN3.5m'           / Specific system
DETECTOR= 's2kb'               / Detector (CCD type, photon counter, etc.)
IMAGETYP= 'OBJECT'             / Type of picture (object, dark, etc.)
PREFLASH=             0.000000 / Preflash time in secs
CCDSUM  = '1 1'                / On chip summation (X,Y)
CCDSEC  = '[1:2043,3:2044]'    / Section in full CCD for DATASEC
CAMTEMP =               -110.3 / CCD Temperature
DEWTEMP =               -176.2 / Dewar Temperature
DATE-OBS= '13/07/97'           / Date (dd/mm/yy) of observation
UTSHUT  = '16:34:45.0'         / UT of shutter open
EXPTIME =               15.000 / Exposure time in secs
DARKTIME=               18.247 / Total elapsed time in secs
DCS_TIME=                 3000 / (ns) DCS integrator slope time
GAIN    = '7.5'                / electrons per ADU
RDNOISE = '14'                 / electrons
READTIME=                20200 / (ns) unbinned pixel read time
WAVEFILE= 's2kb Sat Jul 12 16:02:11 1997' /
RECID   = 'wiyn.imager.970715.064520' / archive ID for observation
UT      = ' 6:45:19.02'         /  universal time
ST      = '18:51:34.34'         /  sidereal time
EL      = '62:55:40.75'        / elevation
AZ      = '-71:26:34.29'       / azimuth
TRACK   = 'enabled'            / tracking
COORDS  = 'Helio. mean FK5'    / coordinate system
RA      = '16:41:49.16'         /  Telescope RA
DEC     = '36:27:13.16'         /  Telescope DEC
RAOFFST = '00:00:0.00'         / Telescope RA offset
DECOFFST= '00:00:0.00'         / Telescope DEC offset
RADECSYS= 'FK5'                / coordinate system
TARGRA  = '16:39:54.19'        / right ascension
TARGDEC = '36:33:16.30'        / declination
EQUINOX =               1997.6 / equinox of position
EPOCH   =               1997.6 / same as EQUINOX (for back compat.)
ZD      =               27.112 / zenith distance
AIRMASS =             1.123176 / airmass at start of exposure
ROTANGLE=                -27.1 / rotator angle, degrees CW from N
FILTERS = 'Harris_B'           / fsa filter name
FILTNUM =                    6 / fsa filter number
FILTWHEL=                    2 / fsa filter wheel
TRIM    = 'Jul 15 15:40 Trim data section is [1:2043,3:2044]'
OVERSCAN= 'Jul 15 15:40 Overscan section is [2049:2080,1:2048] with mean=757.98'
ZEROCOR = 'Jul 15 15:40 Zero level correction image is Zero'
CCDPROC = 'Mar  8 16:03 CCD processing done'
HISTORY New copy of obj0371.imh
WCSDIM  =                    2
LTV2    =                  -2.
LTM1_1  =                   1.
LTM2_2  =                   1.
WAT0_001= 'system=physical'
WAT1_001= 'wtype=linear'
WAT2_001= 'wtype=linear'
FLATCOR = 'Mar  8 16:03 Flat field image is FlatHarris_B with scale=11798.85'