[daip] A problem in CLCOR

[Eric Greisen]

Cheng-Yu Kuo wrote:
>             To whom it may concern:
> 
>         My name is Cheng-Yu Kuo, a UVa graduate student. I may find a 
> problem in the AIPS task CLCOR
> when I applied the troposheric and clock delay calibrations to my VLBI 
> data. When I applied the solutions
> using the "old" version of AIPS, the CL table after the correction just 
> look weird (see the attached figure
> CLCOR_OLD.png) while the CL table after the correction with the new 
> version of AIPS looks ok (
> see CLCOR_NEW.png). Is there any problem with the old version AIPS ? 

You did not define "new" and "old" as to the actual aips version so it 
is a bit hard to answer.  The 31DEC10 version has a bug fix which is 
quite relevant if your vlbi data has only 1 polarization.  It looks like 
the "old" has not applied a correction for the first times and then 
applied too large a correction for the later times.

We recommend that users use a recent version of aips.  For EVLA data 
that version must be 31DEC10 but for all data recent is better.

Eric Greisen