[daip] Updating VLBA correlation parameters

[Andy Biggs]

Hi,

I have a question about updating the correlation parameters for old 
(~1995) VLBA data. I've written before regarding strange distortions of 
gravitational lens images in 'wide-field' (~1"), high dynamic range 
(~500) VLBA data and I'm now seeing the same effect in another lens system.

Running VLBAEOPS updates the values of UT1-UTC and the coordinates of 
the pole used when correlating the data. This causes new delays, rates 
and phases to be written into a CL table. What about the u,v,w's? Should 
these not be updated as well using e.g. UVFIX? This allows the user to 
update UT1-UTC, although the help says very clearly that the default in 
the AN table should be used. Should I actually be using one of the 
updated numbers reported by VLBAEOPS?

Thanks,

Andy

-- 

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

tel. +49 89 3200 6471
fax. +49 89 3200 6898