- NAME
GSSSEXTAST
- PURPOSE
Extract IDL astrometry structure from a ST Guide Star Survey FITS header
- EXPLANATION
This procedure extracts the astrometry information from a ST Guide
Star Survey FITS header and places it in an IDL structure for
subsequent use with GSSSxyad and GSSSadxy.
- CALLING SEQUENCE
GSSSExtast, hdr, astr, noparams
- INPUT
h - the GSSS FITS header
- OUTPUT
astr - Structure containing the GSSS Astrometry information
.CTYPE = ['RA---GSS','DEC--GSS']
.CRVAL = plate center Ra, Dec (from PLTRAH, PLTRAM etc.)
.XLL,.YLL = offsets lower lefthand corner
.AMDX, .AMDY = 12 transformation coefficients
.XSZ,.YSZ = X and Y pixel size in microns
.PLTSCL = plate scale in arc sec/mm
.PPO3, .PPO6 - orientation coefficients
- NOTES
Most users should use EXTAST rather than this procedure. EXTAST will
call GSSSEXTAST if supplied with GSSS FITS header.
- PROCEDURES CALLED
SXPAR() - Extract parameter values from a FITS header
- HISTORY
01-JUL-90 Version 1 written by Eric W. Deutsch
Code derived from Software by Brian McLean
20-AUG-91 Modified to Double Precision Variables. E. Deutsch
June 94 Change astrometry tags to better agree with EXTAST W. Landsman
Converted to IDL V5.0 W. Landsman September 1997
29-JUN-99 Added support for AMD[X,Y]1[2-3] for DSS images by E. Deutsch
Eliminate use of obsolete !ERR W. Landsman February 2000