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:
   An optional file, badframes, can be used to skip images that are bad.
   If it exists, it must contain the file names (no path) of the image(s)
   to be skipped.  This file is expected to be in the current directory.

 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
  2009/08/05, MWB, modified for new rdastfc and astxy2rd versions.
  2009/12/30, MWB, modified for new fitting coefficients methodology
  2012/07/23, MWB, added badframes file support