[daip] Problems on phase-based editing

[I.Marti-Vidal at uv.es]

Hello, AIPS group members,


First of all, congratulations for the great piece of software that is AIPS!

My name is Ivan Marti-Vidal and I'm a PhD student from Spain. I am
analyzing WSRT data with AIPS and I find some problems regarding the
phase-based editing capabilities of AIPS:

I find that, during a lot of long scans of a given source, there are
some bad data points where the phases go from zero to +/- 180 degrees.
This, of course, affects the closure phases, which go from zero to +/-
180 degrees, for the triplets of the affected antennas. The final map
that I obtain is, thus, hardly affected by these bad data points (the
source is point-like, so all the closure phases should be approximately
zero). These abnormal visibilities with phases of +/- 180 degrees are
clearly bad data points that should be edited before running IMAGR. 

I have been looking for a task in AIPS that could allow me to flag data
based on bad visibility phases, but the only thing I have found is a lot
tasks ready to edit data based on bad amplitudes; but none to edit bad
phases. Is there any task of procedure that could help me to edit bad
data, based on abnormal values for the phases?

(I tried to use the DOFLAG option in CALIB, but the bad data is still
there!)

  Thank you very much for your help in advance.

    Have a nice day,

         Ivan