A Phase Synchronization Technique for Multistatic SAR Systems Based on a Microwave Link

Phase synchronization poses a significant challenge for multistatic synthetic aperture radar (SAR) systems. A novel concept called MirrorSAR has been introduced, which relies on a configuration of transmitter and receiver satellites positioned at separate locations. In this setup, the receiver satellites serve as mirrors or space transponders, redirecting the radar echoes back to the transmitter. This arrangement simplifies the receiver functionality and enables the utilization of cost-effective platforms, particularly in the emerging NewSpace domain. Within the transmitter, the forwarded radar signals are coherently demodulated using the same oscillator responsible for generating the radar pulses. This eliminates the need for a bidirectional phase synchronization link between the transmitter and receiver, as observed in TanDEM-X, thus allowing for innovative synchronization approaches that aims to guarantee the bistatic and interferometric performance while keeping the receiver complexity low. This paper further improves the phase synchronization approach based on a microwave link within the MirrorSAR concept. The phase synchronization accuracy is assessed from simulation based on real TerraSAR-X data.