Two dimensional least redundant array for interferometric synthetic aperture radiometer

Synthetic aperture radiometer applies the interferometric principle to sample in the spatial frequency domain and retrieve the image by Fourier or other numerical transformation. Using this technology, a substantial reduction can be obtained compared to a conventional imaging radiometer. In this paper, the study on least redundant two-dimensional array configuration is presented with numerical simulation examples in two types of configurations. One uses half-circle configuration with least redundant number of elements and taking image by rotating the array. The other configuration selects element positions using simulated annealing around a full-circle to provide a roughly uniform distributed sampling coverage in two-dimensional spatial frequency domain. The results show that the number of elements left round the full circle can also reach the least redundant number, i.e. M=C_N², where N is the number of antenna elements and M is the number of different baseline combinations, represent the maximum number of sampling points in the spatial frequency domain.