Raw Data Simulation Under Undulating Terrain for Bistatic SAR With Arbitrary Configuration

Raw data simulation is very important for system parameter design, performance evaluation, and route planning of bistatic synthetic aperture radar (SAR). However, most conventional simulation methods focus on improving the efficiency of echo simulation, without considering the impact of terrain fluctuations, resulting in insufficient fidelity of simulated echoes. In this article, a raw data simulation framework under undulating terrain for bistatic SAR with arbitrary configuration is proposed. In the framework, based on the prior information of digital elevation model of undulating terrain and the small facet theory, the time-variant scattering coefficient is computed first with the empirical formula related with the angle variation of transmitter and receiver for bistatic SAR. Then the shadow is judged from the perspectives of transmitter and receiver, respectively, and the formation of double shadow is discussed. At last, the above process was embedded into the time domain pulse by the pulse echo simulation algorithm, forming a framework for simulating bistatic SAR raw data under undulating terrain with arbitrary configuration, and the simulated and measured data experiments are illustrated to verify the effectiveness of the proposed framework.