The Real-time Imaging Processing Design Of SAR Based On Z7

Since the advent of the Synthetic Aperture Radar(SAR), whether in the military or in the civilian, it has shown its unique advantage and used in more and more widely field after decades of development. With the continuous development of the digital chip technology and unmanned aerial vehicles-related technology, applying synthetic aperture radar to unmanned aerial vehicles and achieving high-resolution real-time imaging have become a new hotspot. This paper focuses on real-time imaging processing technology based on the Xilinx Zynq-7000 and the positive side RD algorithm. The author’s major contributions are outlined as follows:1. The technical advantages to apply Zynq-7000 chip to unmanned aerial vehicles radar have been studied. Based on the historical process of the development of the unmanned aerial vehicles, the technical characteristics of the SAR and the new requirements of today’s technology this paper proposes a new hardware system taking the Zynq-7000 chip as core chip. Because the new unmanned aerial vehicles radar system requires a smaller size, lighter weight and lower power consumption, we choose the latest Zynq chip embedded dual-core ARM made by Xilinx and abandon the traditional FPGA + DSP architectures.2. How we choose the interfaces located in the internal Zynq between PL and PS has been studied. Describes three types of interfaces between PS and PL: Four AXI_GP interface consists of two master interface and two slave interface; Three AXI_HP slave interface, which are controlled by the PL; One AXI_ACP accelerator coherence slave Port, also controlled by the PL. Shows the data throughput and the performance of these three types of interfaces between PS and PL. Through five typical application scenarios in practice shows how to choose these interfaces in order to fully utilize the all Programmable Zynq-7000 chip.3. The design of data communication based on AXI_Stream bus protocol between PS and PL has been studied. Without interface complied with AXI_Stream bus protocol between PS and PL, the paper describes in detail how to create custom IP complied with AXI_Stream bus protocol and introduces its hardware and software design processes. Introduces the capability of AXI_DMA IP transfering AXI_stream protocol to AXI protocol and ability of high-speed data transfer. Both IP core cooperate with each other to ultimately realize high-speed data communication between PL and PS, demonstrate the range of applications of AXI_Stream bus IP and the advantages of AXI_DMA IP in data transmission, and show that,as a PS reconfigurable set, PL has many strengths and differences compared with ordinary peripherals.4. The real-time SAR imaging implementation based on Z7 has been studied. First introduces the structure of the system processing board and explains how to connect the system processor board to inertial navigation systems, servo antennas and microwave modules for their cooperation. Then describes in detail the whole workflow of the radar system and flowing direction of the signal on board. The detailed processes of RD imaging algorithm of the system and the whole algorithm allocation and mapping between multiple cores are described. Finally, describes that when the entire imaging algorithm under real-time requirements in the actual process of debugging could not satisfy our requirement how we could accelerate and optimize it, thus ultimately get the real-time processing. The results show that the micro-based SAR system based on Xilinx Zynq-7000’s,because of its high standard property, has strong practicality and good prospects.