ISOCAM Interactive Analysis User's Manual Version 5.0 - ISO - ESA

348 APPENDIX I. UPGRADING OLD CIA STRUCTURES
CIA> restore, ’old_cvf.xdr’, /verb
% RESTORE: Portable (XDR) SAVE/RESTORE file.
% RESTORE: Save file written by LANDRIU@SAPI01, Thu Jun 12 17:11:05 1997.
% RESTORE: Restored variable: OLD_CVF.
CIA> help, old_cvf.astr, /str
** Structure ASTR_STRUC, 8 tags, length=96:
CD DOUBLE Array[2, 2]
CDELT FLOAT Array[2]
CRPIX FLOAT Array[2]
CRVAL DOUBLE Array[2]
CTYPE STRING Array[2]
LONGPOLE FLOAT 180.000
PROJP1 FLOAT -1.00000
PROJP2 FLOAT -2.00000
This time there are no problems – no other ASTR definition exist in the new CIA session.
Now export old cvf as a FITS file and exit your second CIA session.
CIA> struct2fits, old_cvf, name=’cvf.fits’
CIA> exit
I01[DELANEY]
Returning to your original CIA session, you can now load the FITS file into IDL memory
as a CVF PDS. fits2struct will initialize a new CVF PDS, fill it with data from the old
CVF PDS, and in so doing correct the type of .ASTR.CDELT.
CIA> fits2struct, ’cvf.fits’, hdr, new_cvf
CIA> help, new_cvf.astr,/str
** Structure ASTR_STRUC, 8 tags, length=104:
CD DOUBLE Array[2, 2]
CDELT DOUBLE Array[2]
CRPIX FLOAT Array[2]
CRVAL DOUBLE Array[2]
CTYPE STRING Array[2]
LONGPOLE FLOAT 180.000
PROJP1 FLOAT -1.00000
PROJP2 FLOAT -2.00000
• Due to an error in the original FITS astrometry definition which was propagated into the
ASTROLIB astrometry routines 1 and the CIA routines, roll to crota2 and fits header,
CIA 1.0 CVF.ASTR.CD was defined incorrectly and the CD matrix in FITS files created
1 CIA is distributed with debugged versions of the ASTROLIB astrometry routines: extast, putast, ad2xy,
xy2ad. The location of the CIA version of these routines is placed before the ASTROLIB location on IDL’s
!PATH (if CIA is installed correctly) to ensure that they are compiled first.