[daip] Error in the UVFIX task in AIPS

[Eric Greisen]

Billie Taylor wrote:
> Hi!
> 
> I am having a bit of trouble in AIPS. I was calibrating two different 
> VLA projects in AIPS, and when I got to the first CALIB task where I was 
> calibrating my flux calibrator the task failed without giving me an 
> error message. I reset to default calib and tried again to no avail. I 
> moved on to different projects and a new error is popping up during the 
> UVFIX task. When I run the task, it gives me the error "UVWCAL: ERROR 
>  -1 READING FO/CL TABLE FOR DOPPLER" although the task and the rest of 
> the calibration apparently completes successfully. What does this error 
> mean, and how can I correct it? Also, are the calibrated files still 
> viable despite the error? Thank you for your time!

This message is in fact rather complicated in its cause.  What it is 
saying is that some combination of time, source, and antenna in your UV 
data is not represented in your CL (or FO) table.  These tables are 
supposed to contain a column with Doppler offsets to the frequency.  If 
your data did not  track the Doppler change with time, then the absence 
of this information is not important but it is curious that you have 
some data that is not represented correctly in the CL table.  UVFIX 
could have a better error message and I will fix that.

I am more worried about your other issue.  Does CALIB simply disappear 
or does it die of unnatural causes with no other explanation?  What are 
your inputs?  What does LISTR 'SCAN' say for this data set?

Eric Greisen