Antenna Configuration Evaluation

Melvyn C.H. Wright
Radio Astronomy laboratory, University of California, Berkeley, CA, 94720

In this memo we show that the array performance is improved
by eliminating two stations, reducing the costs of stations,
power and fiber connections and roads, and time spent in antenna
reconfigurations.  The modified C configuration uses station 57
instead of station 33 which was only used in CARMA C configuration.
The modified A configuration uses station 20 from the B configuration
instead of station 8 which was only used in the A configuration.
For each configuration we simulated observations from -2 to +2
hours sampled at 36 sec intervals. In practice, observations will
be interrupted by calibrations and not sampled symmetrically about
transit.  The effects of the proposed changes are smaller than the
effect of the heterogeneous antenna sizes, different weighting,
and non optimum sampling of the data.  We eliminate a NS station
and a section of the loop road and power and fiber distribution.
The modified A configuration has a shorter minimum uv spacing and
more overlap with the B configuration, allowing better calibration
between A and B configurations and more reliable estimates of
decorrelation from atmospheric turbulence.