Specify desired output beam in applybeam step instead of exact operation
Created by: aroffringa
The invert
option of applybeam is confusing. To undo the correction of the beam (invert=false), one has to specify the same direction and mode that were specified during the application of the beam. Better would be to state what is desired as output (i.e.; fully corrected for beam, only for element, only for array, or not at all -- together with the desired direction). With the "new" keywords in the column for the beam, DP3 can then figure out what to do.
(I've tried explaining this beam correction several times to students but it is too complicated to understand!)