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xy2sky



.help xy2sky Mar2001 WCSTools
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NAME
xy2sky \- Compute RA Dec from X Y using WCS in FITS and IRAF image files
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.SH Synopsis
xy2sky [-vbjg] [-n ndec] file.fts x1 y1 ... xn yn
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or
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xy2sky [-bdjgv] [-n ndec] file.fts @listfile
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ARGUMENTS
.ls -a
Append input line after output position
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.ls -b
B1950 (FK4) output
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.ls -d
RA and Dec output in degrees
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.ls -e
Ouput in ecliptic longitude and latitude in degrees.
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.ls -f <number>
Set third dimension for 3-D projections such as CSC
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.ls -g
Galactic longitude and latitude output
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.ls -j
J2000 (FK5) output
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.ls -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
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.ls -n <number>
Number of decimal places in output RA seconds
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.ls -q <year>
Output equinox if not 2000 (-j) or 1950 (-b)
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.ls -t
Output as tab-separated table
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.ls -v
More descriptive output
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DESCRIPTION
.I 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. 
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SEE ALSO
sky2xy(1)
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WEB PAGE
http://tdc-www.harvard.edu/software/wcstools/xy2sky.html
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AUTHOR
Doug Mink, SAO (dmink@cfa.harvard.edu)
.endhelp

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