[evlatests] Time error of 1 WG cycle on array?

[Vivek Dhawan]

Baselines were done after the 5 N arm antennas moved, and
show 2 curious things.

1. There appears to be a systematic position shift of
    every antenna, increasing along each arm, with a
    maximum of 25cm at the ends. Since the velocity at
    at the end of an arm in B array is 50cm/s, this
    corresponds to a time error of about 0.05s, or 1
    waveguide cycle. Could the timing have gone off in
    the recent network changes?

    I do not know when it started, it may be apparent in
    data from last week but that's a job for another day,
    I want to send this message out now.

2. There are small (5mm max error) but unexplained changes
    in the positions that the online system is using for the
    antennas that did _not_ move last week. The database shows
    no change for these antennas since Jan 21, when the last
    baseline update went in. Perhaps this mystery is related
    to the timing error but does not appear to be systematic,
    so i'll ignore it till (1) is fixed.

Vivek.