| imua1
Find USNO-A1.0 Stars in Image Region
|
imua1 is
is a link to the
WCSTools
imcat
utility which finds
all of the
U.S. Naval Observatory A-1.0 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.uac and to standard output if the -v flag is set.
The UA1 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 USNO A catalog.
Set the environment variable UA1_PATH to the directory containing
the region files or UA1_ROOT to the directory below which the CDROMs
(ua001, ua002,...ua010) are mounted. If neither environment variable is set,
the default is to look at /data/ua.
The minimum command line is
imua1 FITS or IRAF filename
The same effect can be obtained by running
imcat -c ua1 FITS or IRAF filename
Examples
- List the 10 brightest USNO-A1.0 Catalog stars in a
FITS image
- List the USNO-A1.0 Catalog stars in a FITS image t
o a file
- Plot USNO-A1.0 Catalog stars onto a FITS image
[WCSTools programs]
[imcat]
[imua2]