GSCALIBRATE

    input = "es*"		    Input spectra to calibrate
    (output = "")		    Output calibrated spectra
    (outpref = "c")		    Output prefix
   *(sfunction = "sens")	    Input image root name for sensitivity function
    (sci_ext = "SCI")		    Name of science extension
    (var_ext = "VAR")		    Name of variance extension
    (dq_ext = "DQ")		    Name of data quality extension
    (key_airmass = "AIRMASS")       Airmass header keyword
    (key_exptime = "EXPTIME")	    Exposure time header keyword
    (fl_vardq = no)		    Propagate VAR/DQ planes
   *(fl_ext = no)		    Apply extinction correction to input spectra
   *(fl_flux = yes)		    Apply flux calibration to input spectra
   *(fl_scale = no)		    Multiply output with fluxscale
    (fluxscale = 1.)		    Value of the flux scale (fl_scale=yes)
    (ignoreaps = yes)		    Ignore aperture numbers in flux calibration
    (fl_fnu = no)		    Create spectra having units of FNU
   *(extinction = "")		    Extinction file