20.22.7 Step_2

Step (2) Extraction of UV visibilities from this map.

From the given input data cube, or the "well behaved" data cube created by Step (1), UV_SHORT computes the visibilities in the following way:

   - Fourier transform of the single dish map;
   - Division by  the Fourier  transform of  the single dish  beam, up  to a
     maximum spacing (SHORT_SD_DIAM, in meters);
   - Inverse Fourier transform to the image plane and then for each pointing
     center;
     - Multiplication of the  image by the primary beam  of the interferometer
       elements;
     - Fourier transform back to the UV plane;
     - Creation  of the  visibilities,  with  a given  weight  SHORT_SD_WEIGHT
       and an appropriate calibration factor to Janskys SHORT_SD_FACTOR.

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