UAV-Borne Bistatic Interferometric SAR Time-Phase Synchronization Technology Based on Bi-Directional Synchronization Chain

The bistatic interferometric synthetic aperture radar (SAR) technology can break through the baseline limitation of monostatic dual antenna interferometric SAR (InSAR), obtain more flexible baseline configurations, and improve the measurement accuracy of long-wavelength InAR, such as L-band and P-band. Bistatic InSAR can play an important role in obtaining understory terrain height through perspective forest observation and carrying out forest aboveground biomass assessment. Aerospace Information Research Institute, Chinese Academy of Sciences led the design and development of China's first UAV-borne L-band bistatic InSAR system, and conducted flight experiments. This paper briefly introduces the system scheme design, basic structure, and main performance, with a focus on the time and phase synchronization technology based on the bi-directional synchronization chain. The first flight experiment scheme and test results are provided to verify the breakthrough of synchronization technology and the basic performance indicators of the UAV-borne bistatic InSAR system. This provides a foundation for the collaborative research of distributed InSAR synchronization technology on multiple UAV platforms in the future.