[evlatests] AR603 21aug06 final report (C + X bands)
Michael Rupen
mrupen at nrao.edu
Tue Aug 22 10:28:20 EDT 2006
AR603 21aug06 07:43-08:43 IAT
------------------------------
mrupen 22aug06
EVLA ant. 13,14,16,18 included
Dynamic run
Standard continuum, C X bands, one fast switching and two "regular" scans
in each band
3.3s averaging
elevation 23-63 degrees (mostly 23-33 degrees)
Fine weather (60% clouds, API 4 degrees)
ODDITIES
On-line flagging seems to have worked _almost_ perfectly for the EVLA.
The one flaw occurs during fast switching scans. The very first source
is fine; but, at every source change within the fast-switching scan,
the EVLA antennas appear first (and obviously off-source) for 2 records;
then everyone vanishes for 10 seconds; then both VLA and EVLA antennas
start appearing, on-source, and indistinguisable from one another.
No sign of missing last record(s), as reported by Rick recently
OVERVIEW
Comparisons are with similar data from 11aug06.
6cm:
ant. 13
IFs AC: terrific, best in the array!
IF B : lousy, worst in the array
IF D : not very good, bottom third
ant. 14
IFs AB: very good, top fifth
IF C : middle of the road
IF D : excellent, one of two best in the array
ant. 16
IFs ACD: one of the worst antennas
IF B : not very good, bottom 1/3rd
ant. 18
superb in all IFs -- best or second best (after 13!) in the array
IF B has an AIPS weight *twice* the median for the VLA !!!
4cm:
ant. 13
IF A much improved -- now among the best!
IF C remains OK (10th of 26)
IF B has gone downhill -- it's now among the worst
IF D remains among the worst
ant. 14 is basically the same -- ok but not outstanding in AC,
lousy in BD
ant. 16 remains superb, among the top antennas
ant. 18 is by far the worst in the array
Tsys is 100-150 K, vs. 30-40 K for the others
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AIPS weights: median ranking, out of a nominal
26 antennas
--> 1 is the best; 26 is the worst <--
6cm 4cm
13-A 1 2
13-C 1 10
13-B 26 25
13-D 18 23
14-A 5 12
14-C 13 23
14-B 4 15
14-D 2 22
16-A 22 4
16-C 24 3
16-B 17 4
16-D 23 3
18-A 2 26
18-C 2 26
18-B 1 26
18-D 1 26
---- ==> 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 <--
6cm 4cm
13-A 1.76 1.37
13-C 1.34 1.10
13-B 0.31 0.43
13-D 0.85 0.62
14-A 1.27 1.04
14-C 1.02 0.76
14-B 1.41 0.97
14-D 1.28 0.71
16-A 0.63 1.20
16-C 0.53 1.25
16-B 0.71 1.20
16-D 0.52 1.26
18-A 1.67 0.05
18-C 1.25 0.05
18-B 2.09 0.05
18-D 1.47 0.03
---- ==> no data
n.f. ==> no fringes (low amp, random phase)
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