Tuesday, July 22, 2008

How does CALIB make use of clean components?

A question from Sam Tun....
I've been working on some self-cal programs for the Owens Valley Solar Array, and I am having similar problems as these. I would want a self-caled map that gives me a good approximation to my CLEAN map fluxes, but no go on that. So, my question is, does anyone know what is done to the clean components to get them to return appropriate visibilities to feed into self-cal? I believe that in AIPS you feed the CLEAN map as a model into calib, but does anyone know the details of what goes on in there (or where to find them)? Gracias.

1 comment:

Laura said...

Well, I'm not really sure of the answer to your question, but I know that there are two basic methods CALIB uses-- 'dft' or 'grid'. Crystal Brogan says that you definitely want to use 'dft'-- it gives a much more accurate model to CALIB. If you leave cmethod='', CALIB will choose between the two methods, and often it will choose 'grid'. So set 'dft' explicitly.

I'm not sure that answers your question though :) I don't really understand the details what 'dft' does.