NAME:
  srcast
 PURPOSE:
  Compute ra,dec for all objects in a source list (see findsrc).
 DESCRIPTION:

 CATEGORY:
  Astrometry
 CALLING SEQUENCE:
  srcast,file
 INPUTS:
  file - File(s) to be read and have ra,dec computed.  The file names are
           expected to end in .src (usually generated by findsrc).
 OPTIONAL INPUT PARAMETERS:

 KEYWORD INPUT PARAMETERS:

  DIR - Directory where .src files are to be found and where .srd files
           will be written.

  OVERWRITE - Flag, if not set this program will skip any files that already
                 have the .srd output file.  Set this to overwrite and
                 regenerate those files.

 OUTPUTS:
  A file is written, the name of the file is the same as the input except
    that the final suffix is changed from .src to .srd.  The output file
    is a FITS format file which is basically a table of numbers. [nobjs,9]
    The contents are as follows:

   Row    Contents
    0     Raw x coordinate of object
    1     Raw y coordinate of object
    2     FWHM of object
    3     Raw instrumental magnitude of object
    4     Uncertainty on the instrumental magnitude
    5     RA of object, J2000
    6     Dec of object, J2000
    7     signal-to-noise ratio of object
    8     Standard magnitude for object.

  Rows 0-4 and 7 are carried forward from the .src file with no change.
  The new columns are computed from the astrometric solution for this frame.

 KEYWORD OUTPUT PARAMETERS:

 COMMON BLOCKS:

 SIDE EFFECTS:

 RESTRICTIONS:

 PROCEDURE:

 MODIFICATION HISTORY:
  Written by Marc W. Buie, Lowell Observatory, 1999/03/18
  2000/01/19, MWB, changed for new version of rdastfc
  2002/01/07, MWB, added DIR keyword
  2002/09/03, MWB, changed Str_sep call to strsplit
  2003/02/21, MWB, added a blank padding character to make sure object name
                      never abuts the file name in the log file.
  2005/05/10, MWB, added OVERWRITE keyword