[daip] [Fwd: problem with a downloaded VLA data file]

[Eric Greisen]

John Benson wrote:
> Hi Eric,
> 
> Am forwarding this to you, I don't know what to tell her.
> 
You did not give me her e-mail so please forward this to her.

> I have downloaded a VLA data archive file 'AG301_1' from
> the NRAO Data Archive System. I am facing a problem
> with it -- after loading in AIPS (using task FILLM),
> it shows only one visibility point for scans on phase
> calibrator. I tried multiple number of times by changing
> settings of FILLM, but it gives the same result. Can you please look 
> into this problem and suggest me a solution. Thanks.
> 

I have loaded these data and the first file was observed with 2-minute 
on-line averaging.  This is very bad practice and was not done with the 
2nd and 3rd files where 1-minute on-line averaging was done.  The 
problem with 2-minute averages is that if the 2-minute cycle is not 
quite complete when the time to leave the source arrives, then that 
2-minute record is lost.  This meant that all calibrator scans except 
for the first were cut short on the first observing day.  It is older 
data and observers were not so knowledgable back then nor was the 
on-line system so capable.

Eric Greisen