Name¶
xy2sky - Compute RA Dec from X Y using WCS in FITS and IRAF image files
Synopsis¶
xy2sky [-vbjg] [-n ndec] file.fts x1 y1 ... xn yn
or
xy2sky [-bdjgv] [-n ndec] file.fts @listfile
Description¶
xy2sky (pronounced X-Y-to-sky) is a utility for getting the world
coordinates of a set of image coordinates in a FITS or IRAF image. World
coordinate system (WCS) information in the image header describes, in a
standard way, the relationship between sky coordinates and image pixels. This
information is used by the program to transform image coordinate (X,Y) pairs
to right ascension and declination sky coordinate pairs. The current version
of the program prints the coordinates at the same equinox as is given in the
image header, but future versions will allow transformations to B1950/FK4,
J2000/FK5, or galactic coordinates. Input and output files in the Starbase
format will eventually be allowed.
Options¶
- -a
- Append input line after output position
- -b
- B1950 (FK4) output
- -d
- RA and Dec output in degrees
- -e
- Output in ecliptic longitude and latitude in degrees.
- -f <number>
- Set third dimension for 3-D projections such as CSC
- -g
- Galactic longitude and latitude output
- -i
- First column is star id; 2nd, 3rd are x,y position
- -j
- J2000 (FK5) output
- -m <number>
- Set mode for output of LINEAR WCS coordinates: 0: x y linear 1: x units y
units 2: x y linear units units
- -n <number>
- Number of decimal places in output RA seconds
- -q <year>
- Output equinox if not 2000 (-j) or 1950 (-b)
- -t
- Output as tab-separated table
- -v
- More descriptive output -z Use AIPS classic projections instead of
WCSLIB
See Also¶
sky2xy(1)
Author¶
Doug Mink, SAO (dmink@cfa.harvard.edu)