UV_CHECK BEAMS

        Identify channel ranges that share a common beam. The raw ranges are re-
    turned  in  variable BEAM_RANGES.  Ranges narrower than BEAM_GAP are ignored
    in determining how UV_MAP derives the weight channels.

      When BEAM_STEP = 0, UV_MAP will attempt to use a single  common  beam  for
    all  channels.  For this purpose, edge channels will be dropped if they have
    weights differing from the majority. They will not be imaged.

    Narrow contiguous ranges of channels with differing weights will not be con-
    sidered in the beam derivation process when the range has less than BEAM_GAP
    channels. These later ignored ranges will be processed with the same weight-
    ing (and thus beam) than all other ones.  They  may  thus  have  sub-optimal
    noise.

        Default BEAM_GAP = 3

    See HELP UV_CHECK BEAM_GAP and HELP UV_CHECK BEAM_RANGES for details.