MAP_ROBUST

      MAP_ROBUST     Real

    Robust weighting factor. A number between 0 and +infty.

    Robust  weighting  gives the natural weight to UV cells whose natural weight
    is lower than a given threshold. In contrast, if the natural weight  of  the
    UV  cell  is larger than this threshold, the weight is set to this (uniform)
    threshold. The UV cell size is defined by MAP_UVCELL and the threshold value
    is in MAP_ROBUST.

    0 means natural weighting, which is optimal for point  sources.  The  Robust
    weighting  factor controls the resolution: better resolution is obtained for
    small values (at the expense of noise), resolution approaching  the  natural
    weighting  scheme for large values.  Larger UV cell size give higher angular
    resolution (but again more noise).

    MAP_ROBUST around .5 to 1 is a good compromise between  noise  increase  and
    angular resolution.