A HIGH-RESOLUTION IMAGING EXPERIMENT WITH MINI-UAV-BASED STEPPED FREQUENCY BFSAR

SAR system can achieve high range resolution by transmitting signals of large bandwidth, which is not easy especially for mini-UAV-based bistatic forward-looking SAR (BFSAR) system due to the platform limitation of load capacity and power consumption. Meanwhile, the bistatic configuration requires high clock synchronization between transmitter and receiver. In this paper, a stepped frequency SAR system is used to obtain high resolution image. Firstly, we introduce the experimental system and the hardware coarse synchronization. Secondly, we use the information of direct-path signal to further compensate the synchronization error, and splice the sub-bands to reconstruct the broadband spectrum. Finally, the effectiveness of the stepped frequency system and the imaging processing are verified by real data.