High Resolution Wide Swath SAR Imaging with Digital Beamforming – Performance Analysis, Optimization, System Design

Abstract:
Multi-aperture synthetic aperture radar (SAR) systems in combination with an appropriate coherent processing of the individual aperture signals enable high resolution wide swath (HRWS) SAR imaging. An innovative reconstruction algorithm for such a digital beamforming on receive (was presented in G. Krieger, N. Gebert, A. Moreira, Unambiguous SAR Signal Reconstruction from Non-Uniform Displaced Phase Centre Sampling; G. Krieger, N. Gebert, A. Moreira, Unambiguous SAR Signal Reconstruction from Non-Uniform Displaced Phase Centre Sampling; N. Gebert, G. Krieger, A. Moreira, SAR Signal Reconstruction from Non-Uniform Displaced Phase Centre Sampling in the Presence of Perturbations; N. Gebert, G. Krieger, A. Moreira, High Resolution Wide Swath SAR Imaging – System Performance and Influence of Perturbations) that allows for HRWS even in case of a non-uniformly sampled data array in azimuth. This paper will compare this algorithm to different azimuth processing strategies regarding their performance in dependency of the overall sampling. Further, the algorithm is characterized theoretically regarding aliasing and residual ambiguities. In this context, optimization strategies are discussed to maximize the system’s performance by pattern tapering on transmit and “Pre-Beamshaping on Receive” networks that adaptively adjust the virtual sample positions.