WCSTools

imusa2
Find USNO-SA2.0 Stars in Image Region

WCSTools programs
imusa2 is a link to the WCSTools imcat utility which finds all of the U.S. Naval Observatory SA-2.0 Catalog objects in a FITS or IRAF image and lists their sky and image positions. 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.usa2 and to standard output if the -v flag is set. The UAC number is the zone ((90 + declination in degrees) * 10) followed by the sequence number of the star within the RA-sorted zone. This number will change with each release of the UA catalog.

Set the environment variable USA2_PATH to the directory containing the CDROM. If the environment variable is not set, the default is to look at /data/usnosa20.

The minimum command line is imusa2 FITS or IRAF filename

The same effect can be obtained by running imcat -c usa2 FITS or IRAF filename

Command Line Arguments

Examples

List the 10 brightest USNO-SA2.0 Catalog stars in a FITS image
List the USNO-SA2.0 Catalog stars in a FITS image to a file
Plot USNO-SA2.0 Catalog stars onto a FITS image

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

Telescope Data Center