[evlatests] AR603 Saturday 9sep06 quick look

[Michael Rupen]

  9sep06: AR603 (03:59-07:29 IAT)
--------------------------------
mpr 11sep06

Preliminary report -- quick fringe check

X C L bands, standard continuum, 3.3s averaging, mostly fast switching scans

"Regular" run

EVLA ant. 13,14,16,18 included (asked for all I could get -- what about 24???)

--------------------------------------------------------------------------------

Summary:
   - good fringes on all antennas at all bands
   - some odd behavior at the beginning of L band (no fringes EVLA-VLA,
     very fast wraps EVLA-EVLA)
   - ant. 16 missing entirely for first fast-switching scans at C, X bands
     : n.b. Tsys _is_ recorded at these times, and shows some sort of
       fast switching going on at C band, though all the uv-data are flagged
   - ant. 18 Tsys is high at C, X bands
   - some bad EVLA data are still leaking through the on-line flags at the
     beginning of some scans, esp. fast-switching sub-scans

--------------------------------------------------------------------------------

Details:
* L band
   - 3C48
     : no fringes on EVLA-VLA baselines
     : EVLA-EVLA baselines show strong and rapidly wrapping (and curved,
       i.e., phases not linear in time) fringes
       e.g., 13-16 and 14-16 cover two turns in under a minute
       13-14 and 13-18 cover about 100 degrees in the same time
       ...uncalibrated amplitudes are about right (same range as VLA-VLA
         baselines)
   - a half hour later, the phases look fine on all baselines

   - Tsys reported as
     ant. 13: 36-55 K
     ant. 14:
       IF AC  35-45 K
       IF BD  24-32 K
     ant. 16: 30-42 K
     ant. 18:
       IF A   25-35 K
       IF C   30-45 K
       IF B   20-27 K
       IF D   25-35 K

     The EVLA antennas do NOT show the much higher Tsys seen at the VLA at
       <30deg elevations

* C band
   - fine fringes for all antennas
   - ant. 16 had no data for first (fast switching) scan, which lasted about
     half an hour.  Tsys are recorded, and show some sort of switching going
     on?!?
   - fast-switching scans: EVLA-EVLA baselines show low amp., offset phases
     for first few records (10seconds-ish) of every sub-scan except the first,
     followed by no data for another 10-ish seconds, followed by nice strong
     phases.
     --> the usual poor EVLA flagging

   - Tsys reported as
     ant. 13: 27-34 K
     ant. 14: 32-40 K
     ant. 16:
       IF A 36-45 K (high end is during first fs scan, where all data were
         flagged by the on-line system)
       IF C 24-32 K (high end is during first fs scan, where all data were
         flagged by the on-line system)
       IF B 36-40 K
       IF D 24-27 K
     ant. 18: IFs AB have high Tsys
       IF A 55-70 K
       IF C 40-52 K
       IF B 50-70 K
       IF D 38-48 K

* X band
   - fine fringes for all antennas
   - ant. 16 had no data for first fast-switching scan (which is the 3rd
     X-band scan), which lasted about half an hour
   - fast-switching scans: EVLA-EVLA baselines show low amp., offset phases
     for first few records (10seconds-ish) of every sub-scan except the first,
     followed by no data for another 10-ish seconds, followed by nice strong
     phases.
     --> the usual poor EVLA flagging
     ...this also occurred for one of the NON-fast-switching scans

   - Tsys reported as
     ant. 13: 28-42 K
     ant. 14: 32-46 K
     ant. 16: 30-45 K
     ant. 18: 55-75 K -- high Tsys in all IFs

================================================================================
================================================================================