Performance analysis of subband STAP for UWB SAR sparse array

In order to improve the angular resolution in a UWB SAR system, sparse array is usually used. However, when using UWB SAR sparse array for moving target detection, its wideband introduces challenges such as high-resolution range migration and dispersion, and the sparse array brings angular ambiguity, which causes blind speed and repeated detection. This paper analyzes the performance of Subband STAP for UWB SAR sparse array. The results show it is not only an effective tool to compensate wideband effects, but also can release the angular ambiguity through subband recombination. We also study the performance of the method versus relative bandwidth, which indicates that a four-channel UWB SAR sparse array with relative bandwidth larger than 46.3% can eliminate blind speed and repeated detection totally via Subband STAP.