Superresolution of coherent targets using aperiodic antenna arrays

A technique for resolving closely spaced coherent targets in the near or far fields of aperiodic antenna arrays is developed in this paper. The practical importance of the aperiodic array is that the array size can be increased without increasing the number of elements. The root mean squared error in estimating the target locations is shown to be lower than that of existing superresolution techniques approximately by the ratio of the array sizes, up to an improvement of two orders of magnitude. Thus for a fixed number of elements (and hence cost) angular estimation accuracy can be materially improved. The validity of this technique is demonstrated with experimental microwave data.