MAKE_PRIMARY

        MAKE_PRIMARY

    This  task  is a linear mosaicing tool, which makes an image cube from a
    set of original CLEAned images (OR from a single CLEANed) image  by  di-
    viding by the primary beam at each location.

    The  original  images are assumed to have the same phase tracking center
    and hence the same map characterictics (pixel, size, coordinates).

    This program compute several images (or rather data cubes) :


         'name'.weight
         'name'.lmv-sky      a  3-d  cube  containing  the   uniform   noise
                            combined  mosaic,  i.e.  the  sum of the product
                            of the fields by the .weight image.


    The image names must derive from a generic name as follows (e.g.  for  a
    generic name "map", and a generic type "lmv-clean")
         map-1.lmv-clean, map-2.lmv-clean,  ..., map-n.lmv-clean
    where "n" is the number of fields.

    The  primary  beam is assumed to be Gaussian. Two parameters are used in
    the mosaic creation: the primary beam width (FWHM), and  the  truncation
    threshold  of  the  primary  beam. It is recommended to use a relatively
    high value for this threshold, 0.2 to 0.4, to avoid contaminating  adja-
    cent field in case of pointing errors.