These are Unix shell scripts which plot star catalogs over FITS or IRAF
imh images which contain a World Coordinate System in their headers.  Each
invokes the WCSTools imcat program to search a star catalog over the region
covered by the image.  This produces an extended PROS-format regions file
which SAOimage then plots over an image.  At the same time, the 'W' cursor
command in SAOimage is set to invoke the WCSTools scat program to find the
star in the specified catalog which is closest to the cursor position and
print out information about it to standard output.

* These scripts expect the Linkbins script to have been run so that scat
and imcat can be invoked with the catalog name as part of the command,
i.e. sgsc and imgsc for the HST Guide Star Catalog.

saoact - USNO ACT catalog from CDROM or hard disk
saobsc - Yale Bright Star Catalog from SAO binary format catalog file
saocata - First argument is catalog name, second is image, reset go to SAOimage
saogsc - HST Guide Star Catalog from 2 CDROMs (or same files on hard disk)
saoiras - IRAS Point Source Catalog from SAO binary format catalog file
saoppm - PPM Catalog from SAO binary format catalog file
saosao - SAO Catalog from SAO binary format catalog file
saoua1 - USNO-A1.0 Catalog from 10 CDROMs (or same files on hard disk)
saoua2 - USNO-A2.0 Catalog from 11 CDROMs (or same files on hard disk)
saouac - Either USNO-A Catalog from CDROMs or hard disk
saoujc - USNO J Catalog from CDROM or hard disk
saousa1 - USNO-SA1.0 Catalog from CDROM or hard disk
saousa2 - USNO-SA2.0 Catalog from CDROM or hard disk
saousac - Either USNO-SA Catalog from CDROM or hard disk

The following two programs do the same overplotting as saogsc and saoua2
above, but invoke scat with the X and Y coordinates of the previous C
cursor command, but search for the star at the current position, with the
closest star AND the previous X,Y coordinates written to standard output as

     x y ra dec

This matching file can than be fed to imwcs in WCSTools 2.9.1 or later,
initializing a world coordinate system fit to the image, using imwcs -u,
or to any other program which fits a world coordinate system.

saomgsc - HST Guide Star Catalog from 2 CDROMs (or same files on hard disk)
saomua2 - USNO-A2.0 Catalog from 11 CDROMs (or same files on hard disk)