[evlatests] WIDAR bronze dataset - C band dual pol.

[Ed Fomalont]

I agree with Frazer that the TSYS should give good estimates of the 
weights.  However, FIXWT does a good job in determining what the 
post-fit (remove the image, look at the rms in the data, baseline by 
baseline or antenna-based) weighting really should be (caveat: my last 
use of FIXWT showed some problems in the technique, mainly too short of 
an averaging time).  In my experience, fiddling with the weighting 
properly does decrease the SNR on the image at the 10 percent level 
(assuming no bad antennas with too high weights are included), but with 
little change in the remaining artifacts.  So my guess is that you don't 
have a major weighting problem, but something more fundamentally strange 
with the data.

Ed