[daip] Source correction with CLCOR

[Andrew Biggs]

Hi Eric. Thanks.

By the way - as part of the recent changes to CLCOR, might this have
screwed up the EPOCH column in the SU table? After running CLCOR, this is
set to 1.157235D+09 and displayed as **** in the header (which is why I
noticed it).

Andy

On 06/08/2012 16:35, "Eric Greisen" <egreisen at nrao.edu> wrote:

>Andrew Biggs wrote:
>> Hi Eric. I have a question about CLCOR versus UVFIX. CLCOR seems to have
>> worked well for the phase calibrator, where the the position shift was
>> only a few mas. I also shifted the target, but by nearly an arcsec. The
>> resultant map of the target was pretty awful and I suspect that this is
>> because the shift was too large. I repeated the calibration without the
>> target CLCOR shift and instead ran UVFIX after all the calibration steps
>> had been carried out. This map looks absolutely fine. So, I think that
>> this is entirely expected behaviour, but just wanted to check with you.
>>
>CLCOR does good phase corrections but does not re-compute u,v,w
>
>A large change in coordinate requires a recomputation of u,v,w.  I
>suspect that doing the shift with CLCOR but then running UVFIX to do the
>re-computation would work as well as doing the shift in UVFIX.  Note -
>CLCOR used to be better than UVFIX for the phases but I improved UVFIX.
>
>Eric Greisen