Sub-band Adaptive Beam Former for Range Ambiguities Suppression in Multi-static SAR Constellations

Abstract

Multi-static SAR concepts are typically operated with insufficient sampling either in Doppler or time domains, and require the coherent combination of the signals of the different receivers to achieve decent ambiguities rejection values. We discuss in this paper the impact of residual co-registration errors in the case of multi-static constellations with large cross-track baselines, and the associated degradation of the performance. We investigate a sub-band reconstruction approach in which we incorporate the signal and ambiguity characteristics in the signal reconstruction process, and test the approach with simulations in a controlled point-target-only scenario. In the final version of the paper, we will discuss the applicability of the suggested approach in distributed scenarios.