[evlatests] Report on AB1248

[Rick Perley]

    Project AB1248 was run, modcomp-free, last evening.  This was a 
'vanilla' X-band file, with no band changes. 

    Observations:

    1)  Antenna 16 was 'partially flagged', on all IFs.  This means that 
near the beginning of the run, some records were being flagged, some 
not.  Later on, all data from 16 were flagged.  By filling the unflagged 
data, I see that the visibilities were fine for the first hour or so, 
following which the antenna fringed on and off.   Something is thus not 
right with this antenna, and the flagger saw it. 
    2) Something bad happened at IAT midnight.  The next calibrator scan 
contained only dead data -- not flagged.  It's clear the operators were 
'right on it', as normalcy seems to have returned by 00:16. 
    3) The program code was not correctly transcribed to the database -- 
it's filed under 'AB124',  not 'AB1248'. 
    4) Antenna 13C fringes extremely weakly, and 13D fringes not at all 
-- none of these are flagged. 
    5) Initial scan flagging is pretty close to being right.   I had to 
remove the initial first records for some antennas -- mostly EVLA -- as 
their amplitudes were low by a few percent.  A small effect, but easily 
seen. 
    6) Phases were as expected for a thunderstormy early evening.  There 
is absolutely no sign of the large phase wind that would be present with 
meter-like errors. 
    7) There are some variable gains (~10%) seen on EVLA antennas 18 (C 
and D), and 26 (C).  Likely related to Tsys issues, but I haven't 
checked this carefully. 

    Otherwise, the data were fine, and should result in a fine map.