[daip] VBGLU in AIPS

[Greg Ball]

Hi Eric,

thanks for your tips regarding MR clean, it seems to be working for me, 
and I will continue to practise.  I have another AIPS query.

I am using VBGLU to reconstruct data which was correlated in 2 passes.
Both input files are in compressed format, as is the output.

I believe that VBGLU constructs the output file using the visibility 
time/baseline values found in the first input file; and that any 
visibilities in the second input file at *other* time/baseline values are 
discarded.   This just amounts to a little lost data, which is fine.

However, I'm not sure what happens when a time/baseline slot from the 
first input file is missing from the second input.

I would guess that the missing data is 'empty' and should have zero 
weight,  but I'm not sure that this is properly represented by the 
compressed data format.  Lincoln Greenhill and Alice Argon here at the CfA 
report that the half-empty visibililities have caused them trouble in the 
past...   however they were using AIPS version from a few years ago.

Thanks,

Greg


--
Gregory H. Ball             Harvard-Smithsonian Center for Astrophysics
Graduate Student            60 Garden St MS #10, Cambridge MA 02138, USA
Astronomy Department        Email: gball at cfa.harvard.edu
Harvard University          Office: +1 617 496-4946