[daip] What does CAL mean in VLBA archive data?

[Lorant Sjouwerman]

On Tue, 20 May 2008, Simon Ellingsen wrote:

#The project in question is BE0014 observed in May 1997 and the archive  
#lists the type of the observation as "cal" rather than "raw", so I  
#assume that some sort of basic calibration pipeline has been run on  
#data?  Is there a description somewhere as to what processing has been  
#done, I've had a look around the archive pages and done some googling,  
#but not turned anything up yet?

I can answer this part of your question:

The archive knows about raw and cal data, which is unfortunate as it 
confuses everyone about the VLBA cal data. So far no solution.

What it is, is preprocessed data, not calibrated. Essentially it is
the data as it should have come out of the correlator, so the basic
administrative programs have run on it in AIPS - not any calibration
or calibration program. But because it has gone through AIPS it is not
raw data anymore and thus is confusingly labelled cal data. We run, if
necessary, some order of VLBALOAD, VLBAMCAL, VLBAFIX (i.e. VLBAFPOL 
and VLBAFQS), MSORT, USUBA, FITAB and some INDXRs in between.

If you're looking for a pipeline, you can try VLBAPIPE. But this is
five year old code so it might not work on your data anymore.


Regards,

Loránt Sjouwerman - Scientific Services - lsjouwerman at nrao.edu
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