[evlatests] Wind-induced lean

[Rick Perley]

    The tests last night were taken with referenced pointing.  The 
solutions showed a peculiar effect -- an approximately 30 arcsecond 
offset in all antennas, seen in either (or both of) Az or El, of either 
sign. 
    Ken put these data (7 observations in widely separated places) 
through his pointing solver, and found that the errors are consistent 
with a steady tilt, in the E-W direction.

    We note that the wind was blowing from the west at the time of 
observation with gusts exceeding 20 mph.  The good news is that 
referenced pointing seems to be able to recover the lean -- I got at 
least semi-decent fringes at Q-band.  But we should note that accurate 
high frequency observing should never be scheduled with winds above 10 
mph (steady).