imgsca is a link to the
utility which finds all of the
GSC-ACT Star Catalog
objects in a FITS or IRAF image and lists their sky and image positions.
The GSC-ACT Catalog is a reprocessed version of the
Hubble Space Telescope Guide Star Catalog,
which purports to remove most of the systematic errors.
World coordinate system (WCS) information
must be present in the image header to describe, in a standard way, the
relationship between sky coordinates and image pixels.
This information is used by the program to find the region in the sky to
search and to transform right ascension and declination sky coordinate pairs
to image coordinate (X,Y) pairs. Output is sent to a file called
filename.gsca and to standard output if the -v flag is set.
The minimum command line is
Find GSC-ACT Stars in Image Region
imgsca FITS or IRAF filename
The same effect can be obtained by running
imcat -c gsca FITS or IRAF filename
- List the 10 brightest GSC-ACT Stars in an image
- List the GSC-ACT Stars in an image into a file
- Plot GSC-ACT Stars over an image using SAOimage