[daip] Problem in FRING

[Walter Alef]

Dear Eric,

I talked to Walter B. and I tested the following procedure which worked:
1) remove overall fringe rate and delay on manual pcal scan(s) (APARM(5)=1)
2) apply solution with CLCAL and 2PT
3) run FRING with APARM(5)=0 on same scan(s) with DPARM(9)=1

To me it seems now that the 'ZRAT' option is just a poor man's approach to the 
problem of independent fringe rate solutions for each IF in the manual 
phase-cal step. As they usually differ only by tens of microHz this is 
sufficient, but not the ideal solution.

Am Mittwoch, 8. August 2012 schrieb Eric Greisen:
> Walter Alef wrote:
> > Dear Eric,
> >
> > I encountered a problem when I tried to fringe fit a data set with 2
> > subarrays in AIPS using FRING to determine IF phase differences (manual
> > pcal).
> >
> > The help files suggests you can run FRING with the adverb SUBARRAY 
> > 0=>all. When determining solutions for a restricted timerange AND data is
> > only in one subarray the program seems to crash (see below) with a not
> > very meaningful error message.
> >
> > Setting SUBARRAY  to the subarray with data works.
> >
> > If the wrong subarray with no data is specified the program aborts with
> > no data selected.
> >
> >
> > localh> FRING1: Task FRING  (release of 31DEC12) begins
> > localh> FRING1: UVGET: Using flag table version   1 to edit data
> > localh> FRING1: AVERT: ERROR  -1 ON INIT DATA FOR READ
> > localh> FRING1:  START SUBARRAY    1 OF    2
> > localh> FRING1:  START SUBARRAY    2 OF    2
> > localh> FRING1: Selecting the data
> > localh> FRING1: Dividing data by source flux densities
> > localh> FRING1: Determining solutions
> > localh> FRING1: CATIO: CATBLK   2 IN USE, CAN'T WRITE
> > localh> FRING1: TABINI: ERROR  4 CATALOGING FILE SN NO   1
> > localh> FRING1: SNINI: ERROR   4 FROM TABINI OPCODE = WRIT
> > localh> FRING1: SNINI: ERROR INITIALIZING SOLUTION TABLE FOR WRIT
> > localh> FRING1: Purports to die of UNNATURAL causes
> > localh> FRING1: vlb067 31DEC12 TST: Cpu=      0.2  Real=      1  IO=     
> >   64 l
>
> I have putbck a corrected FRING - you will get it tomorrow.  It avoids
> the status problem in 2 ways (the second defends against a status from
> some non-FRING source).  The output file writing is now also controlled
> with an adverb and has been cleaned up a little.  Walter Brisken says he
> will see you tomorrow to discuss the new issues you have raised.  Note
> that there is a DPARM(9) option to avoid fitting a rate at all.
>
> Eric Greisen



-- 

        Regards,
                        Walter

Dr. Walter Alef 
Head, VLBI Technology
Max Planck Institute for Radio Astronomy
Bonn, Germany
walef at mpifr-bonn.mpg.de=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
For private email use: walef at netcologne.de ---------------------------------

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