| imusa2
Find USNO-SA2.0 Stars in Image Region
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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
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
