Array Configuration Design for CSRH

The Chinese Spectral RadioHeliograph (CSRH) has two arrays, CSRH-I and CSRH-II. There are 40 and 60 antennas in CSRH-I and CSRH-II, respectively. The shape of antenna array is important to image the sun with interferometry, especially for the CSRH. This paper describes certain analysis and simulations of the array configuration for the CSRH. Several potential configurations are considered, such as the cross shape, Y-shape, spiral shape, and random shape. We selected some parameters to evaluate these configurations according to simulations of solar observations. These include the uniformity in UV coverage, BEAM size, BEAM shape, maximal sidelobe, sidelobe RMS of BEAM, quality of cleaned maps in the UV plane and BEAM domain. Furthermore, costs of construction for these shapes must be considered, because this antenna array would be built in the Inner Mongolia and the optical fibers will be buried in a 3-meter depth. Based on these parameters and quality of cleaned maps, we conclude that the three-arm spiral shape is the best configuration for the CSRH.