John Conway
June 17, 1998
Keywords: Configurations, Infrastructure, uv coverage
In order to reduce the construction and operations costs of the LSA/MMA a large degree of sharing of pads and other infrastructure between different sized configurations is highly desirable. Motivated by this argument logarithmic spiral geometries for the LSA/MMA have been investigated. It is found that certain classes of such arrays with high pitch angle spiral arms, and some random noise in the positioning of antennas along each spiral arm, have uv coverage distributions and naturally weighted beams which are very close to Gaussian. It is argued that for the intermediate sized configurations between 0.2km and 3km such uv distributions and beams are close to optimum. The use of a spiral geometry allows the LSA/MMA to have continuously variable resolution, and allows for the possibility of dispensing with set configurations entirely. If however set configurations are used it is possible to use many configurations with small ratios in size between them (i.e. factors of 2); while only needing to reconfigure about one third of the total number of antennas between configurations. The flexibility of the design means that the operational mode can be decided after construction in response to scientific requirements.
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Last modified: 09 December, 1999
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