[daip] CLCOR and the ATLBA
sean.dougherty at nrc.ca
Wed Jul 4 18:31:18 EDT 2007
I sure you took input from Chris and others on what was required for the
ATLBA. I include a fragment from a recent email from Adam Deller and
his last statement suggests that even he is not 100% sure. I've cc'd
both Adam and Chris Phillips in the hope that they may comment.
Adam's email of 25 june 2007:
"Having dug a little deeper, i believe there is some hard-coding in the
clcor routine which is incorrect. When you run it, do you get something
to the effect "WARNING: This is ATLBA data - ignoring clcorprm(4)",
followed by a similar line about clclorprm(7)? I do. When I went
through the CLCOR.FOR source code, I found it hard-coded ATLBA data to
right handed coordinates and local meridian - wrong on both counts, I
Nevertheless, thanks for the prompt reply. In the meantime, I can make
the necessary changes to CLCOR in my local version to see if I can get
the correct delay/rate/phase solutions.
Eric Greisen wrote:
> 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'
> Eric Greisen
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