Distributed SAR: Impact of Residual Cross-Track Baselines on the Reconstruction Performance in a SAR Train

Abstract

Multistatic synthetic aperture radar (SAR) is one of the proposed approaches to fulfill the ever growing demand for Earth observation data for different applications like Earth science, environmental and hazard monitoring, and reconnaissance. It allows to exploit the NewSpace approach of building many smaller units in a cost efficient way as a complementary concept to full-fledged SAR satellites. The individual satellites fly in a well-controlled formation, but orbit perturbations and possible requirements for an interferometric capability of the system can introduce or even require non-zero cross-track baselines. Here we analyze a SAR-train-like configuration with residual cross-track baselines. This aspect and the underlying topography of the imaged scene need to be addressed during the azimuth signal reconstruction. Those geometrical aspects and the impact of errors in the baseline knowledge are addressed in this paper.