;function update_header
;
;PURPOSE:
;	To add keywords to the fits header of a file generated in 
;	the data reduction for the H4RG Images. 
;	
;	The keywords are taken from the KeyStr structure that is
;	instantiated at the beginning of each script
;INPUTS:
;	FitsHeader: The header to be updated
;
function update_header, FitsHeader

common KeyParams

;Ramp Parameters
FxADDPar, FitsHeader, 'NREADS',   KeyStr.NReads, 'Number of Reads per Group'
FxADDPar, FitsHeader, 'NGROUPS',  KeyStr.NGroups, 'Number of Groups in Ramp'
FxADDPar, FitsHeader, 'NDROPS',   KeyStr.NDrops,  'Number of Drops per Group'
FxADDPar, FItsHeader, 'TOTREADS', KeyStr.TotalReads, $
	'Total Number of Reads in Ramp'
FxADDPar, FitsHeader, 'FILTER',   KeyStr.ThisFilter, 'Filter Used'

;Pointing/WCS Parameters
FxADDPar, FitsHeader, 'RA',      KeyStr.RA, 'Right Ascension (Hours)'
FxADDPar, FitsHeader, 'DEC',     KeyStr.DEC, 'Declination (Degrees)'
FxADDPar, FitsHeader, 'ZD',      KeyStr.ZD,	'Zenith Distance (Degrees)'
FxADDPar, FitsHeader, 'AZ',      KeyStr.AZ,      'Azimuth (Degrees)'
FxADDPar, FitsHeader, 'HA',      KeyStr.HA,      'Hour Angle (Hours)'
FxADDPar, FitsHeader, 'LST', 	 KeyStr.LST,	'Local Sidereal Time'
FxADDPar, FitsHeader, 'UT', 	 KeyStr.UT,	'Universal Time (Hours)'
;Calculate airmass using routine by E. Gawiser - RA and DEC are bad
;KeyStr.AirMass = airmass(KeyStr.LAT,KeyStr.DEC,KeyStr.HA)
KeyStr.AirMass = 1/cos(KeyStr.ZD*!pi/180.)
FxADDPar, FitsHeader, 'AIRMASS', KeyStr.AIRMASS, 'Airmass'
FxADDPar, FitsHeader, 'LAT',     KeyStr.LAT,	'Latitude of Observatory'
FxADDPar, FitsHeader, 'ITIME',   KeyStr.ITIME,	'Integration Time'
FxADDPar, FitsHeader, 'CDELT1',  KeyStr.CDELT1,  'Degress Per Pixel'
FxADDPar, FitsHeader, 'CDELT2',  KeyStr.CDELT2,  'Degrees Per Pixel'
FxADDPar, FitsHeader, 'CRVAL1',  KeyStr.CRVAL1,'RA at Frame Center, J2000 (deg)'
FxADDPar, FitsHeader, 'CRVAL2',  KeyStr.CRVAL2,'DEC at Frame Center, J2000 (deg)'
FxADDPar, FitsHeader, 'CTYPE1',  KeyStr.CTYPE1,'Right Ascension'
FxADDPar, FitsHeader, 'CTYPE2',  KeyStr.CTYPE2,'Declination'
FxADDPar, FitsHeader, 'CRPIX1',  KeyStr.CRPIX1,'Origin for Coordinates X'
FxADDPar, FitsHeader, 'CRPIX2',  KeyStr.CRPIX2,'Origin for Coordinates Y'
FxADDPar, FitsHeader, 'TIME',    KeyStr.Time,  'Time of exposure'
FxADDPar, FitsHeader, 'MCD_FILE',KeyStr.MCDFile, 'Name of .mcd file used for expos.'
FxADDPar, FitsHeader, 'WINDOWM', KeyStr.WindowMode, 'Window Mode = 1; Full Frame=0'

return, FitsHeader

end