A novel ultra-wide swath SAR based on variable PRF and Digital Beamforming

To realize the ultra-wide swath SAR imaging with a fine resolution, which enables a shortened revisit time for frequent global mapping, an innovative multiple elevation beam (MEB) SAR based on variable PRF and Digital Beamforming (DBF) with the reflector antenna is proposed. Such a system employs DBF technique to effectively improve SNR and suppress the range ambiguities, and the use of deployable reflector antenna avoids the implementation complexity compared with the planar antenna. Furthermore, a novel strategy of linear variation of pulse repetition interval (PRI) is effectuated to overcome the blind-range problem of the conventional MEB SAR. The system configuration and imaging scheme are described in detail. A typical example spaceborne SAR based on the presented technique is designed. Simulation results denote that the presented SAR system shows satisfactory performance.