An Advanced Lightweight Dual-Band Digital Array SAR System: Earth Observation Imaging and Moving Target Detection

High-resolution synthetic aperture radar (SAR) imaging has great application potential in terrain mapping, oceanographic observation, air-to-ground reconnaissance, and regional surveillance. Low cost, lightweight, and multiple modes are important trends in the future development of SAR systems. The Aerospace Information Research Institute, Chinese Academy of Sciences (AIRCAS), developed a state-of-the-art X/P dual-band lightweight digital array SAR system (X/P-DASAR) with a compact unit weighing less than 20 kg, which can be easily installed in a wide range of aircraft. This system adopted the integrated design of the X/P dual-band to realize the common aperture of the dual-band antenna, and employed digital beamforming (DBF) technique to enable multiple radar modes such as large-swath scanning imaging, SAR high-resolution imaging, and detection of slow and small ground moving targets. Furthermore, it implements on-board real-time processing of currently multimode received data. X/P-DASAR serves as a test bed for the development, implementation, and testing of advanced radar technique applicable to Earth observation imaging and moving target detection. In 2021, airborne test flights of the X/P-DASAR system were conducted in Meishan, Sichuan, China. The data processing results verified the system's excellent capabilities of 0.1 m high-resolution imaging and 4 km/h ground slow moving target detection.