AIPS HELP file for ONEBEAM in 31DEC22
As of Sun Feb 5 19:44:41 2023
Type: Adverb (scalar)
Use: To specify whether one beam is made for facet number 1 and
applied to all facets or whether separate beams are computed for
each facet. Technically, each facet should have a separate beam
since the u,v distribution is slightly different for each
facet. Since uv-plane Clean as done in IMAGR is an adaptive
algorithm, the model containing any minor errors made in the
minor Clean cycles due to the error in dirty beam will be
correctly subtracted from the residual visibility data and the
next cycle will attempt to undo those errors while refining the
model. Using ONEBEAM TRUE will speed up IMAGR by a bit and
probably will not affect the answers much. Very high dynamic
range imaging should be done with ONEBEAM FALSE.
Null value: <= 0 -> Compute beams for each facte
> 0 -> compute one beam and apply it to all facets
IMAGR........Fourier transforms and Cleans uv data with wide-field,
interactive TV, and data weighting options.
ONEBEAM affects how many beams are computed and used
and this will affect the speed and accuracy of the
SCIMG........Full-featured imaging plus self-calibration loop with
editing. Same as IMAGR.
LINIMAGE.....Build image cube from multi-IF data set.
TDEPEND......Time-dependent imaging procedure "step 3".