[daip] CLCOR and the ATLBA

[Eric Greisen]

Sean Dougherty writes:
 > Eric,
 > 
 > I have recently been trying to calibrate a test VLBI experiment with the
 > ATLBA using the Swinburne software correlator. Unfortunately, there was
 > an error in the position of one of the antennas used in the array and
 > running CLCOR was required to fix the problem. The ATLBA has a
 > left-handed coord system and uses Greenwich meridian. Using the
 > supposedly correct values for CLCORPRM(4)=0 (for LH) and CLCORPRM(7)=0
 > (for Greenwich) according to the help files did not produce the
 > satisfactory solutions for delay, rate and phase as expected.
 > 
 > After exploring a number of potential solutions (none of which worked)
 > in conjunction with Ed Fomalont (NRAO) and Adam Deller and Chris
 > Phillips in Australia, a close examination of the aips code for CLOCOR
 > shows that when the array is 'ATLBA' that it is NOT possible to use
 > these values for the ATLBA. The code is written such that VLA, ATCA and
 > ATLBA are hardwired to be RH and use local meridian (!&*@^#%$).
 > 
 > Any chance of modfying the CLCOR code so that it works correctly?
 > 

CLCOR does what the AT people (e.g. Chris Phillips) told me it should
do.  Have they changed their minds?

Since you are already familiar with the code - a specific suggestion
for a code revision would be a good idea.  The number of places
affected is not trivial:

primate<929>$ AIGREP ATLBA $TST '*.FOR'
/home/primate/AIPS/31DEC07/APL/SUB/NOTST/GETTIM.FOR
/home/primate/AIPS/31DEC07/APL/PGM/NOTST/GETJY.FOR
/home/primate/AIPS/31DEC07/APL/PGM/NOTST/ACCOR.FOR
/home/primate/AIPS/31DEC07/APL/PGM/NOTST/PCCOR.FOR
/home/primate/AIPS/31DEC07/APL/PGM/NOTST/CLCOR.FOR
/home/primate/AIPS/31DEC07/APL/PGM/NOTST/SPLIT.FOR
/home/primate/AIPS/31DEC07/APL/PGM/NOTST/SPLAT.FOR
/home/primate/AIPS/31DEC07/APL/PGM/NOTST/UVCRS.FOR
/home/primate/AIPS/31DEC07/Y/PGM/NOTST/LOCIT.FOR
/home/primate/AIPS/31DEC07/Y/PGM/NOTST/CLPLT.FOR
/home/primate/AIPS/31DEC07/Y/PGM/NOTST/VPLOT.FOR
/home/primate/AIPS/31DEC07/Q/PGM/NOTST/CVEL.FOR

Eric Greisen