[evlatests] Progress on WIDAR Imaging Woes (fwd)

[Michael Rupen]

---------- Forwarded message ----------
Date: Tue, 14 Jul 2009 13:50:48 -0600
From: Rick Perley <rperley at aoc.nrao.edu>
To: Michael Rupen <mrupen at nrao.edu>
Subject: Re: [evlatests] Progress on WIDAR Imaging Woes

    It is a Deep Red Herring.  I have used Eric's new UVFIX, and it perfectly 
reproduced the (u,v,w) that you have.  All the signs and conventions are 
correct, so far as I can tell.  In any event, it won't cause the problems we 
have found today...

Rick

Michael Rupen wrote:
>  Hi folks --
>
>     Eric reminds me that he gave a special UVFIX for Rick, which did
>  reproduce the uvw's given by the filler.  So the real question is whether
>  the antenna coordinates are correct...which (1) would not explain
>  the problems Ed & Rick see, and (2) would not (I assume!) give
>  baseline-based
>  problems.
>
>     So I think this is a red herring (sorry!), though I guess Rick might
>  have a look at his (VLA vs. WIDAR) data set...
>
>               Michael
>
> 
> >  Hi Ed --
> > 
> > 
> > 
> > >   Has anyone checked to see if the u,v for antennas 25 and 28 are 
> > >   correct?
> > > 
> >  Rick checked the uvw's, and I thought also compared UVFIX with the uvw
> >  from the filler.  Is this right, Rick?
> > 
> > 
> > >   UVFIX does very bad things, even for the other good antennas.  This
> > >   implies that the antenna positions in the data base may be in error,
> > >   even if the u,v's are okay?
> > > 
> >  The uvw's are generated from the antenna positions in the filler, so
> >  at the pre-CASA stage they were presumably OK.
> > 
> >  Obviously we should track this down however.  Vivek, Rick, have either
> >  of you compared UVFIX with "filled" uvw values?
> > 
> >                   Michael
> > 
> > 
> > 
> > 
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