Research And Implementation Of Signal Processing Technology For Small Three-coordinate Search Alert System

With the development of military-civilian integration,the demand for civilian search alert radar in the civilian security market has increased,making high-cost,high-power large-scale alert radars gradually develop toward low-cost and low-power consumption.The civil search alert radar is a small search alert system.Its target of concern is different from that of military radar,and it is limited by factors such as cost,radio control,application environment,etc.So there are problems such as echo signals being susceptible to interference and poor detection accuracy.Therefore,the development of a high-performance,low-cost,fully functional small search alert radar system has a great application value.The three-coordinate search alert system detects moving targets,provides information on the distance,speed,azimuth,and altitude of the target,and can track specific targets.The signal processing module in the search alert radar system studied in this paper is the core part of the radar system.The research content involves the principle of signal processing algorithm,signal processing hardware platform,and algorithm implementation and verification based on this hardware platform.In this paper,the main principles of signal processing algorithms in the search alert radar system are analyzed in detail,including digital down conversion,pulse compression,moving target indication,moving target detection,constant false alarm detection,and angle measurement.Among them,the angle measurement algorithm is a key algorithm,and the performance of the angle measurement algorithm directly affects the spatial positioning ability of the small three-coordinate search alert system for moving targets.Then based on the application scenarios of lidar,the similarities and differences in the algorithm are analyzed,and the scalability of the research in the field of laser radar is illustrated.The signal processing hardware platform adopts the "FPGA+DSP" architecture,which combines the parallel processing capability of the FPGA with the flexibility of the DSP.Mainly complete two tasks: signal processing and communication,where communication includes communication between processor chips and communication between hardware platform and other system sub-modules,ensuring that data throughput requirements are met,thereby realizing data transmission,information exchange,parameters updates and commands delivery.In the implementation of signal processing algorithms,this paper makes full use of hardware and software resources to complete real-time detection and spatial positioning tasks for moving targets.The feasibility of FPGA-based multi-path parallel algorithm and DSP multicore parallel algorithm is verified by simulation data and measured data.The phase difference correction formula is also proposed for the phase difference between antenna channels in actual engineering.The high-precision angle measurement in the threedimensional space is realized,and the algorithm implementation scheme is verified in the field experiment.