AIPS HELP file for ROBUST in 31DEC25
As of Mon Feb 10 9:55:24 2025
HELP SECTION
ROBUST
Type: Adverb (Real)
Use: The robustness parameter, devised by Daniel Briggs, is
used to temper the effects of uniform weighting. Thus,
the weight actually used for sample i is
F1 (Wi)
WT = ----------------------
[F2 (Wj)] + S
where F1 and F2 are 2 functions applied to the input
weights (Fi (W) = W by default), the [ ] means the sum of
the F2 of the Weights of all samples in the neighborhood
of the i'th sample, and S is a function of ROBUST. We use
(10**(ROBUST)) * <[F2 (Wj)]>
S = --------------------------------
5
where < > denotes the average of the local sums over all
visibilities. Note that if ROBUST > 4, the weight sums
have little effect and the weighting is close to natural
weighting. If ROBUST < -4, then S is very small and we
have virtually pure uniform weighting with no tempering.
Null value: NONE
Tasks:
IMAGR.........Fourier transform and Clean UV data with a full range of
calibration (application), weighting, Cleaning, and
wide-field correction options.
SCIMG.........Full-featured imaging plus self-calibration loop with
editing.
SCMAP.........Imaging plus self-calibration loop with editing.
UVIMG.........Grid UV data into an "image". If DOROBUST > 0, then
uniform weighting with AIPS standard ROBUST is done.
Procedures:
CXIMAGR.......Grid UV data into a complex image, Fourier transform,
Clean - calls UVIMG.
LINIMAGE......Build image cube from multi-IF data set.
MAPPR.........Simplified access to IMAGR.
OBITIMAG......Access to OBIT task Imager without self-cal or peeling.
OBITMAP.......Simplified access to OBIT task Imager,
OBITPEEL......Access to OBIT task Imager with self-cal and peeling.
OBITSCAL......Access to OBIT task Imager with self-cal, NOT peeling.
TDSTEP3.......Time-dependent imaging procedure "step 3"
TDSTEP5.......Time-dependent imaging procedure "step 5"
Y2KSAVE.......Verifies correctness and performance using standard
problems.
EXPLAIN SECTION