NAME:
  mosastrom
 PURPOSE:   (one line only)
  Astrometry solution for multi-detector image sets
 DESCRIPTION:
 CATEGORY:
  Astrometry
 CALLING SEQUENCE:
  mosastrom,name,xoffset,yoffset,rotang
 INPUTS:
  name    - String that defines the name of the image to process
  xoffset - Vector, one element per image in the mosaic, that describes
               the offset of each relative to the optical axis.  The actual
               definition is that this is the X position of the optical
               axis in the native pixel coordinates of each image.
  yoffset - Vector, one element per image in the mosaic, that describes
               the offset of each relative to the optical axis.  The actual
               definition is that this is the Y position of the optical
               axis in the native pixel coordinates of each image.
  rotang  - Rotation of each image relative to the anchor image. (radians)
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  ANCHOR - Number of the image that is the anchor upon which the
              monolithic coordinate system is to be based.  The default
              is the one whose (0,0) pixel is closest to the optical axis.
              Note that this value is a number that points into the
              input xoffset,yoffset arrays and starts at 0.
  KEYLIST  - Name of a file containing a correspondence list. This list
                associates a set of standard names with the actual keyword
                names found in a FITS file header. If this keyword is
                omitted, a default list is used (see loadkeys.pro)
  NEWTERMS - String array with the names of the terms to use in the fit.
              Default=use the terms as found in the initial astrometric
              solution.
  NEWRENORM - This keyword allows you to change the renormalization
                 factor for the astrometric solution.  The default is
                 to use the value that is found in fitcoeff.dat.
  PATH   - String, name of the directory where the images can be found.
              Default=current directory
  CATDIR - Sring, name of the directory where the catalog files can be found
              default is the current directory
  SRCDIR - String, name of the directory where the source files can be found
              Default='Src' (relative to the current directory).
  REFDIR - STring, name of the directory where the correlated star/catalog
              lists are stored, Default='Refstars'
  SUBARU - Flag, if set indicates that the file and naming scheme from
              the Subaru Observatory is to be used (individual files for
              each image in the mosaic).  If this not set the default
              file behavior is to look for a multi-group FITS file that
              contains all images in one file.
 OUTPUTS:
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  2010/01/14, Written by Marc W. Buie, Southwest Research Institute