Configurations of the six-antenna array

The six-element array can be arranged in the following configurations:

Conf	Stations
A	W27	E68	N46	E24	E04	N29
B	W12	W27	N46	E23	E12	N20
C	W12	E10	N17	N11	E04	W09
D	W08	E03	N07	N11	N02	W05

The general properties of these configurations are:

$\circ$

A alone is well suited for mapping or size measurements of very compact objects. It provides a resolution of $0.8''$ at 100GHz, $\sim$0.35$''$ at 230GHz.

$\circ$

B alone yields $\sim$1.2$''$ at 100GHz and, in combination with A provides an angular resolution of $\sim$1.0$''$ at 100GHz. In addition, because it contains long, intermediate and some short baselines, it could still be used in a tapered mode when a project is observed in marginal weather conditions despite some loss of sensitivity (for backup projects). It is mainly used for relatively strong sources.

$\circ$

C provides a fairly complete coverage of the uv-plane (low sidelobe level) and is well adapted to combine with D for low angular resolution studies ($\sim$3.5$''$ at 100GHz, $\sim$1.5$''$ at 230GHz) and with B for higher resolution ($\sim$1.7$''$ at 100GHz, $\sim$0.7$''$ at 230GHz). C alone is also well suited for snapshot and size measurement experiments.

$\circ$

D alone is best suited for deep integration and coarse mapping experiments. This configuration provides both the highest sensitivity and the lowest atmospheric phase noise.

The four configurations can be used in different combinations to achieve complementary sampling of the uv-plane, and to improve on angular resolution and sensitivity. Mosaicing is usually done with D or CD, but the combination BCD can also be requested for high resolution mosaics. Check the ANY bullet in the proposal form if the scientific goals can be reached with any of the four configurations or their subsets.

Please consult the documentation on the Plateau de Bure configurations and the IRAM Newsletter No. 63 (August 4th., 2005: ../IRAMFR/ARN/aug05/aug05.html) for further details.