SAOimage display of M-51

SAOimage Implementation of
Multiple World Coordinate Systems

 SAO/TDC Home Page
SAOimage 1.29 implements the use of multiple world coordinate systems, with the WCS to which a keyword applies designated by a suffixed upper-case alphabetic character.

Thus CTYPE1 applies to the default WCS, which may be named using WCSNAME. A second WCS could use keywords such as CTYPE1A and WCSNAMEA. Up to 27 (no suffix, A-Z) different sets of WCS keywords may be specified.

In SAOimage, the WCS to be used is specified by adding %WCSNAME to the end of a filename specified on the command line. This is added after the extension of a multi-extension FITS image is specified: 

fitsfile,extension_name_or_number%WCS_name_or_letter
An additional nonstandard feature has been added, the keyword WCSDEPx, which is set equal to the name of a WCS which would be found in a WCSNAMEx keyword value or a single character which is assumed to be the suffix for the WCS.

Last updated 11 July 2001 by Doug Mink dmink@cfa.harvard.edu

[<B>WCSTools</B>] [SAOimage WCS]