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.