These subroutines extract parameters from FITS headers and use the
resulting data structure to convert image pixel coordinates to sky
coordinates and vice versa. They are used in several image viewing
programs and so are distributed with
I/O and access subroutines
in wcssubs.tar.gz
as well as in libwcs/ in wcstools.tar.gz.
dsspos.c
dsspos( ) uses the WCS structure to compute sky coordinates given
image pixel X and Y for images with Digitized Sky Survey plate solutions
in their headers. dsspix( ) uses the WCS structure to compute image
pixel X and Y given sky coordinates for DSS images. (Algorithms from
StSCI CASB)
platepos.c
platepos( ) uses the WCS structure to compute sky coordinates given
image pixel X and Y for images with polynomial plate solutions
in their headers. platepix( ) uses the WCS structure to compute image
pixel X and Y given sky coordinates for those images.
tnxpos.c
tnxpos( ) uses the WCS structure to compute sky coordinates given
image pixel X and Y for images with IRAF polynomial plate solutions
in their headers. tnxpix( ) uses the WCS structure to compute image
pixel X and Y given sky coordinates for those images. (Translated to C
from IRAF SPP subroutines written by Lindsey Davis, NOAO)
Subroutines for extracting WCS information from a FITS image header.
wcslib.c lin.c cel.c proj.c wcstrig.c sph.c
WCSLIB subroutines for 26 proposed FITS standard projections by
Mark Calabretta of CSIRO.
worldpos.c
worldpos( ) uses the WCS structure to compute sky coordinates given
image pixel X and Y for images with header information for any of 8
standard world coordinate systems. worldpix( ) uses the WCS structure
to compute image pixel X and Y given sky coordinates for the same images.
(Expanded from AIPS-based subroutines by Bill Cotton of NRAO)
zpxpos.c
zpxpos( ) uses the WCS structure to compute sky coordinates given
image pixel X and Y for images with IRAF polynomial plate solutions
in their headers. zpxpix( ) uses the WCS structure to compute image
pixel X and Y given sky coordinates for those images. (Translated
from SPP to C by Frank Valdes, NOAO)
fitshead.h
Declarations of FITS header and image access subroutines and FITS
table data structure.