MirrorSAR Concept: Phase Synchronization Analysis

Phase synchronization is one of the key challenges for multistatic synthetic aperture radar (SAR) systems. MirrorSAR is a recently proposed concept, which is based on a set of mutually separated transmitter and receiver satellites. The main functionality of the receiver satellites is reduced to a kind of microwave mirror (or space transponder) that routes the radar echoes towards the transmitter, considerably simplifying them and enabling the use of low-cost platforms like those being developed in the NewSpace context. The forwarded radar signals are coherently demodulated within the transmitter using the same oscillator that generated the radar pulses. This avoids the need for a bidirectional phase synchronization link between transmitter and receiver, as in TanDEM-X, and enables new synchronization approaches that, while maintaining bistatic and interferometric performance, keep the MirrorSAR receiver complexity low. This paper investigates the accuracy of the Double-MirrorLink concept for phase synchronization of a MirrorSAR system. Following the definition of a signal model that accounts for the various phase error sources, some preliminary simulation results regarding phase synchronization accuracy are shown.