[daip] CLCOR position shifting

[Eric Greisen]

Mark Reid wrote:
> Dear DAIPser:
> 
>     I have been trying to debug some procedures (runfiles) for our VLBA 
> Key Project for parallax measurements.  As a test I observed/correlated 
> some calibrators at their correct positions and offset by ~1 arcsecond.
> I then FRINGe fit the data, getting delays and rates, and then solve for 
> position offsets.  This seems to work well.
> 
> However, when I correct the data processed at the offset positions by 
> running CLCOR (ANTC), I no longer get any FRINGe solutions.  Before I 
> spend a lot of time figuring out what I may have done wrong, I thought I 
> would ask if there is any chance that (31Dec09) CLCOR does not "know" 
> that the Y-station coordinates have been changed?

No.  There is a chance that one or more antennas do not have the correct 
Y due to a bug affecting FITLD and so the pre-processed data in the 
archive.  We are fixing it but it probably is not yet done.

Use RUN ANCHECK and then ANCHECK on your file.  It will fix any wrong Y 
and tell you about it.

Eric Greisen