[daip] 31DEC14 AIPS - Change in behaviour of CLCAL for de-selected SOURCES

[Eric Greisen]

Michael Bietenholz wrote:
> Happy New Year Eric
> 
>  I noticed that CLCAL in 31DEC14 writes out CL table records even for
> sources deselected by the SOURCES adverb. (In 31DEC13 it would not
> write out such records).
> 
> Was this an intended change?  It seems to just pass an unmodified version
> of the input CL table through for those sources.  THis behaviour is 
> probably
> safe and perhaps even more useful than that of the old version, I'm just 
> checking that this was an intended change.
> 
> (For complicated CLCAL's I would check the number of CL table records
> as a quick check that I hadn't lost a bunch of data due to missing 
> calibration;
> which check no longer works now;  one has to be careful in such cases
> that one does not wind up with some unintended mixture of updated and
> un-updated CL records)
> 
>            cheers,          michael

This behavior is controlled by the adverb OPCODE with CALP (for pass) 
the new default.  Too many CL tables were gradually losing entries for 
scans and sources in a way that was not intended.  A bug in the 
application code (actually many bugs) caused it to apply CL records for 
source A to source B and/or to interpolate over vast distances in time. 
  Since CL tables have source-dependent values (elevation corrections in 
phase, gain, position corrections, antenna position corrections, etc.) 
one cannot interpolate between sources.  I fixed that starting with 
changing the OPCODE default Feb 20, 2013.  From then into June I 
gradually solved all the ramifications of requiring a CL table record to 
apply to the current source and even had another fix in October.  All 
this was in 31DEC13 - there are no changes in 31DEC14 from 31DEC13.

Eric