[daip] CLCAL bug

[Zsolt Paragi]

Hi,

I think there is a bug in CLCAL. I am doing the a-priori
amplitude calibration of the EVN Network Monitoring
Experiment. In some IFs much Tsys data are missing for one
telescope. CLCAL does not interpolate between Tsys
measurements (more accurately, between the gain points
determined by APCAL), when there is a source change.
I thought CLCAL should apply solutions regardless of
source, if not specified otherwise.

We use AIPS 31DEC02 (last updated on 2 Oct 2002), but we
see the same problem with previous releases, too. Our
inputs are mostly defaults:

sources ''; calsour ''
antennas 0
opcode ''
interpol '2PT'
cutoff 0
gainuse 1; gainver 2;
refant 1

We played with the parameters, e.g. we tried to specify calsour
explicitly (by typing in all sources), changed the reference
antenna, opcode etc. I also tried giving a large value (1000 mins)
value to cutoff (interpolation limit time), but it did not help.

I have seen the same problem recently at another experiment, too.
This was a phase-referencing project. For one telescope in one
IF there were Tsys data available only for the calibrator. CLCAL
did not interpolate the gains for the faint target source, and
the data were lost.

With regards,
Zsolt

======================================================================
  Zsolt Paragi                        |  Tel.   :  +31 521 596 536
  EVN Support Group                   |  Fax    :  +31 521 596 539
                                      |
  Joint Institute for VLBI in Europe  |  E-mail :  paragi at jive.nl
  Postbus 2, 7990 AA Dwingeloo, NL    |
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