UV_SHORT

        UV_SHORT

    This task prepares a UV table of short spacings from a  single-dish map.
    This  table  may  later  be  merged  to an interferometer UV table.  The
    operations performed are:
      -  Fourier transform of the single dish map
      -  Division by the Fourier transform of the single dish  beam,  up  to
        a maximum spacing (SD_DIAM$, in meters)
      -  Inverse Fourier transform to  the  image  plane
      -   Multiplication  of  the   image   by  the  primary  beam  of   the
        interferometer elements
      -  Fourier transform back to the UV plane.
      -  Creation of the UV table, with a given  weight  SD_WEIGTH$  and  an
        appropriate calibration factor to Janskys SD_FACTOR$

    Both the single-dish and the interferometer antennas are assumed to have
    gaussian beams (SD_BEAM$ and IP_BEAM$, in radians).