For ROBUST, beam sizes and noise level (in flux and brightness) will be computed for 9 different MAP_ROBUST weighting parameters (from Start to Start*Step9̂). Default value for Step is sqrt(10), and default value for Start is derived to center the "robust" parameter values around 1. UV cell size is taken from variable MAP_UVCELL, and Taper is taken from variable UV_TAPER.
The /PLOT option will display the inner regions of the beams.