Does IRAF support world coordinate systems in images?
IRAF does support various coordinate systems in addition to the pixel array coordinates. This was described in IRAF Newsletter #12, July 1992, “World Coordinate System Support in IRAF V2.10”. These coordinate systems are specified in the image headers under specific keywords. The most common type of world coordinate system is linear. The linear coordinate systems are de- scribed using the standard keywords defined by the basic FITS documentation. Hence images in FITS with linear coordinates can be easily imported into IRAF. The astronomical celestial projections are also supported. This follows a description similar to current FITS proposals. A description of the syntax used in IRAF is given in the help for the task WCSEDIT. This task may be used to create or modify such world coordinate systems. There are more complex non-linear coordinate systems used in spectra. These are described in the document The IRAF/NOAO Spectral World Coordinate Systems (specwcs.ps.Z) in the IRAF documentati
