[daip] Shifting maps and UVSUB'ing

[Andrew Biggs]

Hi Eric. This is perhaps a slightly bizarre question. I have a very bright
source in my primary beam which I wish to peel. I have made a very nice
map of it via lots of experimentation (with self-cal'ing, clean boxes,
etc.) by shifting the u,v data to the location of the source using UVFIX
and then heavily averaging the data in both frequency and time to try and
suppress any contamination from other sources in the field. I mainly did
this because it's much, much quicker to experiment.

In this way I end up with a fantastic map of the source and a good SN
table. My question is, after applying the SN table, can I subtract this
map directly from the *unshifted* data? The coordinates in the map's
header are clearly okay, but I worry about the part of the header that says

"Phase shifted in X  -1002.213  in Y   -881.334".

Is this a problem?

Cheers,

Andy