[daip] RE: responses - big confusing sources/BP selfcalibration

[Namir E. Kassim]

> 4. confusing sources way out? - i forget how far i looked - i think at
>     least 20 degrees - didn't see any obvious problems. had imagr work
>     on fields that were 5.7 degrees across for each pointing.
>

that's reasonable. just take five minutes to flip through the back of Kraus
(3c catalog) to reasure yourself that any of the super biggies (e.g. Virgo,
Hydra, especially for D array P band) aren't lurking out at slightly beyond
20 degrees. (or the sun.)

you used SETFC, right? you can always run it and search out to 90 degrees.
you don't need to use the output to drive IMAGR, but just let it track down
your screen so you can see what's out there. you want to do that once just
as a safety net.

i'm trying to think of other things that would lead to discrepency for the
same sources in different fields - i'm afraid the PB asymetry has got to be
the leading candidate.

you did this in spectral line mode, right? how did you make your BP tables?
which source did you use, how did they look, and did you make them time
variable or not? we've found something new recently, that calls for "BP
self-calibration" and it seems to help 74 and P band (sometimes). basically
we end up using selfcal to make BP corrections which are both time and
frequency dependent. maybe you don't want to know about it ... but if you
keep struggling and are scratching for every way to eak out a bit better
fidelity, i can tell you more about it. it's straight forward but a little
tedious.

-Namir