[daip] gain missing in APCAL

[Arnaud Collioud]

Hi Amy,

Thank you! That makes sense now!
To avoid this, I will probably be more careful in the separation of the IFs (using UVCOP as you did).

Cheers,
Arnaud

Le 17 sept. 2014 à 00:29, Amy Mioduszewski a écrit :

> Hi Arnaud,
> 
> I figured out the problem, but it is one of those complicated things that there could be bugs in various tasks connected to it, so it might take a bit to have a final fix.  There are a few easy work arounds though.  The issue is the spurious 2nd freqid that exists in the data.  If you do a PRTAB (INEXT='FQ') or a LISTR it will show you this FREQID.  Anyway, there seems to be a few minutes of autocorrelation on antenna 4 with FQ#2.  So when ANTAB loads the TY table it assigns some Tsys entries to FQ#2, and when APCAL encounters these entries, it looks for a GC entry for FQ#2 and doesn't find one.  I think I might add the FREQID to that error message since that would have helped diagnosing the problem.  This also explains why I didn't get this error when I UVCOPied the data because I only copied FQ#1.  The easiest work around is to explicitly set FREQID=1 in APCAL.  I tested this and it worked.
> 
> The question is how this situation could be handled better in AIPS.  I suspect the autocorrelations are "real" so how could AIPS have done things differently?
> 
> Cheers,
> 
> Amy