Hardware Design For High-Frame-Rate VideoSAR Real-time Signal Processing System

As a new microwave observing system,Video Synthetic Aperture Radar(Video SAR)has been applied to generate high precision video images for ground targets and areas day and night under all weather conditions.Compared with optical and infrared sensors,Video SAR has the advantage of high-resolution imaging in degraded visual environments such as bad weather,cloud,explosive soot and smoke.Additionally,compared with traditional SAR,Video SAR extends the time dimension of information acquisition,which has a stronger ability to acquire information on moving targets.Video SAR has the characteristics of high frame rate and high data throughput,which requires high processing capacity,transmission bandwidth and real-time performance of signal processing system.Based on the research of high frame rate Video SAR imaging algorithm,a highly parallel and scalable real-time signal processing system is designed by standardization,modularization and digitization according to the characteristics and performance requirements of Video SAR.The main contents of this dissertation are as follows:1.Video SAR imaging method with high frame rate is studied.Video SAR imaging principle,working mode and its characteristics and advantages compared with traditional SAR are introduced.Video SAR resolution and frame rate characteristics are analyzed,and the deduction process of relevant formulas is given.Aiming at the problem of long pulse accumulation time and repeated calculation of data overlap in frequency domain algorithm,the traditional BP algorithm has a large amount of computation and a long time-consuming.A parallel Video SAR algorithm based on sub-image fusion is introduced in detail.The number of operations and the of the algorithm is analyzed.The effectiveness of this method is verified by point target simulation.2.A real-time signal processing system for high frame rate Video SAR is designed.The design requirement of real-time signal processing system for high frame rate Video SAR is analyzed,and the technical specifications of the system are given.A highly parallel and scalable system architecture which follows Open VPX standard is designed by adopting standardized and modular design methods.High-speed serial interconnection technology and high-speed serial switching technology are used to realize high-speed data transmission between boards.The design of signal acquisition board,high-speed and large-capacity storage board and multi-function switchboard is briefly introduced.3.A high performance heterogeneous signal processing board is designed and debugged.The hardware circuit design of the signal processing board is completed,and two DSP with 8GB DDR3 SDRAM,FPGA,SRIO switch and Gigabit Ethernet switch are integrated in the single board.The common signal integrity problems in the design of high-speed circuit PCB are summarized,and then the PCB design of the processing board is completed.Based on the designed signal processing board,the application and development of the high-speed serial bus are completed,which indicates that the Hyperlink bus has a transmission rate of 28.45 Gbps,the SRIO bus has a transmission rate of 12.5 Gbps,and Gigabit Ethernet has a transmission rate of 376 Mbps.