Multi-DSP Joint SAR Real-Time Imaging System Based on PFA Sub-Aperture Imaging Algorithm

The Synthetic Aperture Radar(SAR) real-time imaging system designed with multi-DSP architecture has been widely used in both airborne and satellite platforms. In the context of real-time imaging systems, Polar Format Algorithm(PFA) fall short of meeting the system’s real-time demands. This paper proposes a multi DSP architecture SAR imaging system based on sub-aperture PFA to meet the real-time imaging requirements. The system utilizes multiple sub-aperture echo data to design a "2+1" DSP C6678 hardware architecture, and implements the sub aperture PFA algorithm in parallel on the hardware to improve imaging efficiency. Furthermore, we performed phase gradient autofocus processing on the imaging results and achieved high-resolution images. The experimental results show that compared with traditional PFA, the proposed sub aperture PFA algorithm and hardware architecture reduce imaging time by 54%.