[daip] Assistance with Flagging Issues in AIPS {External}

[Lieuwe de Regt]

Dear designated AIP,

I am a PhD student at ASTRON and Radboud University, working with my supervisor, Dr. Pikky Atri (cc’ed), on reducing VLBA data using AIPS. However, I’ve encountered some issues related to flagging, and I would appreciate your advice.

In my data, there are sudden variations in the system temperature, which I have flagged using UVFLG (see figure BM500_SystemTemperatureSpikes.png in the attachments).
When I run the task VLBAAMP, the output indicates that the subtask ACSCL is using the FG table I created. However, upon examining the CL table with the gain corrections produced by VLBAAMP, it does not seem like any areas have been flagged, i.e., the flagged spikes still persist (see figure BM500_PersistentAmplitudeSpikes in the attachments).

To circumvent this, I attempted to flag the TY table directly using SNEDT. This created a new version of the TY table with the flagged areas removed. However, running VLBAAMP again results in the same outcome, with the flagged areas seemingly not being applied.

At this point, the only way forward I can see is to flag the CL table produced by VLBAAMP. However, this would mean the sudden variations in system temperature would have already influenced the amplitude calibration, which is not ideal.

Am I missing something in the procedure, or could this be a potential issue in AIPS?

Thank you for your time and for maintaining AIPS!

Kind regards,
Lieuwe de Regt


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listmgr.nrao.edu/pipermail/daip/attachments/20241128/ffb29747/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: BM500_SystemTemperatureSpikes.png
Type: image/png
Size: 17991 bytes
Desc: BM500_SystemTemperatureSpikes.png
URL: <http://listmgr.nrao.edu/pipermail/daip/attachments/20241128/ffb29747/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: BM500_PersistentAmplitudeSpikes.png
Type: image/png
Size: 28921 bytes
Desc: BM500_PersistentAmplitudeSpikes.png
URL: <http://listmgr.nrao.edu/pipermail/daip/attachments/20241128/ffb29747/attachment-0003.png>