[evlatests] antenna 28 pointing still bad

[Ken Sowinski]

On Fri, 14 Nov 2008, Ken Sowinski wrote:

> A more careful examination of the data taken for the pointing
> runs suggests that the antenna misbehaves at low elevations.
> There were many, but not all, scans below 20 degrees in which
> the amplitude response for antenna 28 was essentially zero, or
> more than an order of magnitude smaller than the other antennas.
> There is weak evidence that the degradation is not caused by
> pointing.  For one scan there was sufficient response on one
> baseline to see that the pointing offsets were not large at all.

Barry wondered if the antenna was trying to look through the barn.
Indeed that explains the low amplitudes.  All the scans which
failed were looking low within an azimuth range of 170 to 200
degrees.  These scans do not contaminate the pointing model
solution because they were easily recognizable as bad and discarded.