[daip] Problems with NX table in VLBI/VSOP data

[Andy Biggs]

Hi Eric,

You're a genius. There are regular occurrences of autocorrelations for 
antenna 4 and if I run UVCOP with UVCOPPRM(3)=1 I can remove them and 
then INDXR runs correctly. I seem to have successfully read in all the 
files now and things look fine.

Thanks very much for your help.

Andy

On 30.10.18 17:12, Eric Greisen wrote:
> On 10/29/2018 05:39 PM, Andy Biggs wrote:
>> Hi Eric,
>>
>> I had already run UVSRT (I tried MSORT as well) and that doesn't fix 
>> the problem. I don't think there are any subarray issues.
>>
>> The problem seems to be the following. The scan order is the following:
>>
>> 1 source   = J1041+06
>> 2 source   = J1033+07
>> 3 source   = J1033+07
>> 4 source   = J1033+07
>> 5 source   = J1033+07
>> 6 source   = J1058+01
>> 7 source   = J1033+07
>>
>> If I UVCOP 1041 and 1033 and run INDXR, it seems to be totally unaware 
>> of the gap where J1058+01 (scan 6) is supposed to be. This gap is 
>> about 5 minutes, but INDXR with CPARM=1,0 will not find it. Therefore, 
>> AIPS really seems to think that these sources were observed at the 
>> same time and thus interleaves them in the NX file.
>>
> 
> Try running prtuv in the time range from the middle of scan 5 to the 
> middle of scan 7.  If you set dparm(6) to 1, you will get the random 
> parameters and so can see the source number and the time.  If INDXR is 
> unaware of scan 6 when having only J1033+07, then there are data points 
> of J1033+07 in that interval as well as data points of J1058+01.
> 
> Eric

-- 

Andy Biggs
ARC Astronomer, ALMA Regional Centre
European Southern Observatory
Karl-Schwarzschild-Straße 2
D-85748 Garching
Germany

tel. +49 89 3200 6471
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