[evlatests] Temporal phase drifts

[Rick Perley]

    Vivek mentioned in the WIDAR Monday meeting that although phases now 
connect beautifully, there is some evidence of phase drifts.  I've 
checked this with the 6-hour C-band database that was taken on 
Saturday.  The results, based on using antenna 28 (N8) as reference:

    Antenna 3's phase (both polarizations, all subbands) declines 
steadily by 60 degrees through the time interval. 
    Antenna 24's phase (both polarization, all subbands) declines 
steadily by 70 degrees throughout.
    Antennas 8, 9 and 27 all have a similarly-shaped rise in phase by 
~20 degrees, occuring over the final hour only. 

    All other antennas show zero drifts. 

    Antenna 3 is at E9, antenna 24 at W5, antenna 8 at N1, antenna 9 at 
E6, and antenna 27 at E3.  There seems to be no simple explanation for 
these drifts on the basis of array position.