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UV_STAT Casa

        CASA and GILDAS handle the weighting scheme slightly differently and
    with different conventions for the Robust parameter values.

    CASA uses only Briggs weighting, while IMAGER offers the Briggs  weight-
    ing  scheme (obtained for MAP_ROBUST < 0) and a different, more progres-
    sive, weighting (obtained for MAP_ROBUST > 0).

    For MAP_ROBUST < 0, the corresponding CASA Briggs value can be  obtained
    by adding 2.

    In addition, CASA apparently uses a default value for the size of the UV
    cell in Briggs weighting  which  is  about  the  dish  diameter(*).   If
    MAP_UVCELL is 0, IMAGER will use the same default value.  Otherwise, IM-
    AGER will use the specified user input.

    (*) The default value quoted before is valid for a single field.  Howev-
    er,  the  documentation is unclear in this respect and suggests that the
    UV cell size depends on the imaged field size. This  would  be  strange,
    though. What happens for mosaics is even less clear.


Gildas manager 2023-06-01