define	SZ_GEISTIME	24	

#  GET_MJD1 -- Obtain the observation time of input file's first pixel
#
#  Description:
#  ------------
#  Get the absolute observation time of the first pixel in MJD.  This version
#  is not final because we don't know how to get the absolute time to very
#  high accuracy (<1 sec) yet. -- JCH April 1992.
#  
#  Header parameters:
#  -----------------
#  "CRVAL1"		first pixel time
#
#  Date		Author			Description
#  ----		------			-----------
#  11-Apr-1990  J.-C. Hsu		original
#  19-Jun-1992  J.-C. Hsu		get time from CRVAL1 (MJD)
#------------------------------------------------------------------------------

procedure get_mjd1 (ipin, mjd1)

pointer	ipin		# input: input file pointer
double	mjd1		# output: modified Julian date of the first pixel

double	imgetd()
#==============================================================================
begin
	mjd1 = imgetd (ipin, "CRVAL1")
end