[daip] Re: CLCOR position shifts (fwd)

[Andreas Brunthaler]

Leonia Kogan wrote:
> Andreas,
> 
> You wrote:
> 
> 
>>The J2000 coordinates are the same in the SCHED output and the SU-Table. 
>>The apparent coordinates are different from the SU-Table.
> 
> 
> I think this is the answer.
> 
> Can you edit your original SU table (ofcource copiing it before) by TABED
> to get the apparent coordinates identical with SCHED output?
> 

If I use TABED with optype='repl', the new values in the SU table are 
not identical with the input values. Even if I use double precision. But 
the error I make with the first shift gets much smaller with the 
improved apparent positions.

> 
> Socorro correlator use only epoch coordintes. FITLD (in AIPS) calculates 
> the apparent coordinates and put them into SU table. Approximately  a year
> ago, we found a mistake in FITLD's calculation of the apparent coordinates.
> 
> So if you FITLDed your data long time ago you could have a mistake in
> the apparent coordinates at the SU table.

Yes, I FITLDed the data over one year ago. Then I wrote the data on tape 
and used FITLD now to load it again. The the old and wrong SU-Table was 
porbably loaded as well. I'll try to load the raw data again and see if 
it works.


Andreas