Catalogs and Surveys Group
is publically available but "unsupported" software developed
by STScI to recontruct a DSS image for any position in the sky. Developed
platforms, it is used internally at STScI to provide images of the sky
to the astronomical community.
- original release
- Improvements to handle CDROMs under Unix
- Added CDROM jukebox capability
- Added capability to specify individual plates. NFS mounted jukeboxes
- Incorporated CFITSIO package, restructured plate list files.
- V3.0 - modified to include improved astrometry using the GSC-II/ICRS for
HST cycle 15 onwards, and now includes standard FITS WCS keywords.
code (5MB tar) | plate
lists (1MB zip) | image headers (90MB
The DSS headers returned by GetImage V3.0 are significantly different
from those returned by earlier versions.
- They have been restructured in a more logical manner for human readability.
- The latest FITS standard keywords have been used wherever possible
- some old keywords have been replaced or dropped (eg. EPOCH) and new
have been added.
- The headers now contain a primary HDU and either
one or two FITS Table extensions.
- The new header contains THREE (3)
astrometric calibrations - PLEASE be sure you know what your software
- The previously existing GSC-I astrometric coefficients for the original
survey plate are retained in the header for backward compatibilty but
should NOT be used for HST observation planning from cycle 15 onwards
when HST switches to using GSC-II.
- The new GSC-II astrometric coefficients for the original survey plate
have been added to the header along with the astrometric correction
- A new set of FITS WCS keywords that correspond to a local gnomic
approximation to the GSC-II astrometry. This is dynamically
computed and inserted into the headers as the image is returned to
the user. This is the preferred astrometry to use - most software
does not handle GSC-II astrometry but can use the new FITS WCS.