WCSTools

imgsca
Find GSC-ACT Stars in Image Region

WCSTools programs
imgsca is a link to the WCSTools imcat 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
imgsca FITS or IRAF filename
The same effect can be obtained by running
imcat -c gsca FITS or IRAF filename

Command Line Arguments

Examples

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

Last updated 30 July 2002 by Doug Mink dmink@cfa.harvard.edu

Telescope Data Center