Investigation on Spatial Resolution and Synchronization Aspects in Airborne Bistatic SAR

Abstract

Synthetic Aperture Radar is a radar imaging tech- nique widely used in the field of Earth observation. In bistatic SAR, transmitter and receiver are located on independently- moving platforms, introducing a higher number of degrees of freedom in the design of acquisition campaigns. On one hand, this allows for larger baselines, simultaneous acquisitions, and measurement of scattered waves at incident angles impossible for monostatic missions. On the other hand, additional technical challenges arise when operating two independent platforms, and the analysis of the system imaging properties becomes more challenging. One major issue is the decorrelated phase noise introduced by the transmitter and the receiver, which leads to synchronization errors between the two and phase errors in the acquired data. In this work, a bistatic SAR point-target simulator and a time domain backprojection processor were developed and employed as tools to evaluate the imaging performance of general bistatic acquisition geometries in terms of simulated system impulse response function, and to investigate the effectiveness of a phase noise correction method based on the exchange of synchronization pulses between the two platforms