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Some useful information is contained in the header of the
calibSlit files. Nearly all of this infomation is carried through
the pipeline and is present in the headers of spSlit, slit, and
spec1d files. To access the header of a calibSlit file, use the
GODDARD routine headfits as follows IDL> hdr = headfits('calibSlit.2200.004B.fits', ext=1) which reads the header corresponding to the 1st extension in the file. Another GODDARD routine, hprint is very useful for viewing the header. The syntax for this command goes like IDL> hprint, hdr Executing this command will display the header info in an easily read 3 column format. The first column gives the header keyword name, column two displays the value corresponding to that keyword, and the third column (preceeded by the slash) is a comment field providing additional information regarding the keyword. To access a header field, use the GODDARD routine sxpar as in this example: IDL> maskname = sxpar(hdr, 'SLMSKNAM') IDL> hprint, hdr XTENSION= 'BINTABLE' /Written by IDL: Fri Apr 11 22:02:05 2003 BITPIX = 8 / NAXIS = 2 /Binary table NAXIS1 = 26079696 /Number of bytes per row NAXIS2 = 1 /Number of rows PCOUNT = 0 /Random parameter count GCOUNT = 1 /Group count TFIELDS = 11 /Number of columns COMMENT COMMENT *** End of mandatory fields *** COMMENT COMMENT COMMENT *** End of mandatory fields *** COMMENT EXTNAME = 'calibSlit' /Extension name DATE = '2003-04-12' /Creation date FRAMENO = 15 / OUTFILE = 'd0813_ ' / EXPTIME = 0.972000000000 /exposure time in seconds of arc DARKTIME= 1.44400001000 / OBSERVER= 'Faber, Coil, Schiavon, Wirth @ HQ' / OBJECT = '2200.E; NAKX' / OBSTYPE = 'Object ' / ROTATVAL= 36.7662200900 / DATE-OBS= '2002-08-13' /date yyyy-mm-dd of observation UT = 0 / AIRMASS = 1.16257304000 / TARGNAME= '2200.E ' / EPOCH = 0 / EQUINOX = 2000.00000000 / DEC = '+34:49:35.3' / RA = '16:49:55.39' / AZ = -54.5483756800 / EL = 59.3020421200 / HA = '+02:02:13.17' / ST = '18:52:14.28' / MJD-OBS = '52499.324898' / PARANG = 111.072392820 / SYNOPSIS= '1 s, Object Spectral 2200.E/1200G/OG550 Kr Xe Ar Ne' / DWFILNAM= 'OG550 ' / SLMSKNAM= '2200.E ' /slitmask name GRATEPOS= 3 /grating position: slider 3 or 4 HPLOGTIM= 'Mon Aug 12 21:41:38 HST 2002' / COMMENT COMMENT *** Column names *** COMMENT COMMENT COMMENT *** Column names *** COMMENT TTYPE1 = 'FLAT ' / TTYPE2 = 'IVAR ' / TTYPE3 = 'MASK ' / TTYPE4 = 'SLITFN ' / TTYPE5 = 'X0 ' / TTYPE6 = 'X1 ' / TTYPE7 = 'DLAM ' / TTYPE8 = 'LAMBDAX ' / TTYPE9 = 'TILTX ' / TTYPE10 = 'RAWFLAT ' / TTYPE11 = 'RAWARC ' / COMMENT COMMENT *** Column formats *** COMMENT COMMENT COMMENT *** Column formats *** COMMENT TFORM1 = '1531904E' / TFORM2 = '1531904E' / TFORM3 = '1531904B' / TFORM4 = '374D ' / TFORM5 = '4096E ' / TFORM6 = '4096E ' / TFORM7 = '374E ' / TFORM8 = '6D ' / TFORM9 = '3D ' / TFORM10 = '1531904E' / TFORM11 = '1531904E' / COMMENT COMMENT *** Column dimensions (2 D or greater) *** COMMENT COMMENT COMMENT *** Column dimensions (2 D or greater) *** COMMENT TDIM1 = '( 4096, 374)' / TDIM2 = '( 4096, 374)' / TDIM3 = '( 4096, 374)' / TDIM10 = '( 4096, 374)' / TDIM11 = '( 4096, 374)' / COMMENT DCS header cards taken from arc image SP2DVERS= 'v1_1_1 ' /Version of spec2d AUTHOR = 'Finkbeiner & Davis' / CHIPNO = 1 /chip number for this slitlet GRATING = 1200.06000000 /rule of grating GRTLTWAV= 7800.01367188 /Nominal central wavelength SLITNO = 1 /slit number SLITX0 = 650.268 /center of trace SLITX1 = 1023.67 /center of trace SLITWID = 0.731000 /slit width in mm MASKPA = 27.5000 /Mask PA on sky SLITPA = 27.5000 /Slit PA on sky X0SYNTH = /Was X0 synthesized from other traces? X1SYNTH = /Was X1 synthesized from other traces? WAVETYPE= 'POLYFLAG' /wavelength solution method END IDL> The comments in red font are not set by the pipeline and have been added in this documentation to aid the user. |