[evlatests] EVLA status: AR603, 23jul06 (Sunday)

[mrupen at nrao.edu]

AR603 23jul06  17:36-19:06 IAT
------------------------------
mpr 24jul06

Report of data quality (as measured by AIPS weights)

EVLA ant. 13,14,16,18,24 included

Standard continuum, C X L bands (L band uses L1 setup)
3.3s averaging
elevation 13-54 degrees
OK weather (cumuliform clouds, API 3-4 degrees)

OVERVIEW
 20cm:
    ant. 13 
      IFs AC no fringes
      IFs BD horrible (worst or next-to-worst antenna)
    ant. 14 pretty bad -- bottom quartile
    ant. 16 
      IFs AC bad (bottom quartile)
      IFs BD horrible (worst or next-to-worst antenna)
    ant. 18
      IF  A  horrible (worst in array)
      IF  C  no fringes
      IFs BD best of all EVLA IFs -- puts this in the top third of the antennas
    ant. 24 no data

  6cm:
    ant. 13 no data
    ant. 14 is excellent, as usual
      no phase jumps when changing bands
    ant. 16
      IFs AC very unstable amplitude gains, and very low quality (worst
        antenna by far)
      IFs BD were quite good (among top 4 antennas)
      no phase jumps when changing bands
    ant. 18 no data
    ant. 24 no data
  
  4cm:
    ant. 13 
      IFs AC no frings
      IF  B pretty good (upper quartile)
      IF  D middle of the pack
    ant. 14 lousy (near the bottom), except IF A is in the middle 
    ant. 16 fine (upper quartile)
    ant. 18 
      IFs A & B were middle-of-the-road
      IF  C no fringes
      IF  D near the bottom
    ant. 24 horrible (near the bottom in all IFs) -- IF C esp. bad 

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

AIPS weights: median ranking, out of a nominal
  26 antennas
  --> 1 is the best; 26 is the worst <--

        20cm   6cm   4cm  
  13-A  n.f.  ----  n.f.
  13-C  n.f.  ----  n.f. 
  13-B   26   ----    5 
  13-D   25   ----   12.5

  14-A   19.5   1    14   
  14-C   24     4    25   
  14-B   19     2    20   
  14-D   16     2    26   

  16-A   21    26     5   
  16-C   20    26     6   
  16-B   25     3     6   
  16-D   26     4     4   

  18-A   26   ----   15   
  18-C  n.f.  ----  n.f.  
  18-B   10   ----   15   
  18-D    7   ----   23   

  24-A  ----  ----   26
  24-C  ----  ----   26 
  24-B  ----  ----   23
  24-D  ----  ----   24

  ---- ==> no data
  n.f. ==> no fringes (low amp, random phase)

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

AIPS weights: median fractional weight
  mean weight is calculated for each record
  fractional weight is the weight for the EVLA antenna,
    divided by that mean
  the median fractional weight is the median value of the
    fractional weights, derived from the distribution across
    all records in which the antenna was present
  --> high is good <---
  --> the average VLA antenna is 1.0 <--
  --> 0.1 is 10 times worse than the average;
     10.0 is 10 times better <--

        20cm   6cm   4cm  
  13-A  n.f.  ----   n.f.
  13-C  n.f.  ----   n.f.
  13-B  0.65  ----   1.17
  13-D  0.64  ----   0.99

  14-A  0.87  1.55   0.97 
  14-C  0.69  1.23   0.42
  14-B  0.88  1.59   0.85
  14-D  0.95  1.42   0.37

  16-A  0.82  0.39   1.16
  16-C  0.83  0.30   1.17
  16-B  0.73  1.45   1.14
  16-D  0.32  1.19   1.20

  18-A  0.52  ----   0.95
  18-C  n.f.  ----   n.f.
  18-B  0.99  ----   0.95
  18-D  1.08  ----   0.73

  24-A  ----  ----   0.40
  24-C  ----  ----   0.03
  24-B  ----  ----   0.78
  24-D  ----  ----   0.73

  ---- ==> no data
  n.f. ==> no fringes (low amp, random phase)

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