Design And Implementation Of Signal Processing Algorithm For High-speed Target Detection In SF-LFM Pulse Rada

As the environment of the modern war becomes more and more complex,the emergence and increasing μse of varioμs high-speed combat platforms,the development of target feature control technology,and the technical difficulty of target detection and recognition have greatly increased.The ability to distinguish,identify,select,and track presents new challenges.In this situation,high-range resolution radar appears spontaneoμsly.Based on the subject of high-speed target detection by high-range resolution radar,this thesis carried out the research and development of a high-speed target detection signal processor based on frequency-modulated stepped pulse radar.The development of high-range-resolution radar and the significance of research are briefly described,and the advantages and disadvantages of the existing typical high-range-resolution radar signal system are summarized,and two high-resolution pulse-to-pulse frequency stepping and Stepped Frequency-Linear Frequency Modulation are emphasized.The specific work is as follows:First,for the SF radar signal processing,this paper establishes an echo model and analyzes the process of one-dimensional high-resolution range profile.Based on the above analysis,This paper presents a speed estimation method based on the minimum legitimate method and the multiple pulse interval pulse group frequency domain range profiles cross correlation method.In this method,the echo pulse groups with different pulse intervals are grouped and subjected to frequency domain cross-correlation processing,and then the waveform entropy of HRRP is compared and analyzed by the minimum legitimate method,and the final velocity estimation result is obtained.The simulation results prove that this method has a speed estimation accuracy of less than 0.8m/s at a signal-to-noise ratio of about 15 dB,which meets the accuracy requirements of speed compensation.Aiming at the SF-LFM ledar which combines the advantages of SF and LFM ledar,the target echo model of high-speed targets is established,the pulse compression processing of the chirp sub-pulse is analyzed,the signal processing flow of high-resolution range imaging is also described as follows.Based on the above research,this paper designs a high-accuracy phasederived velocity measurement method for high-speed targets based on SF-LFM signals.This method μses wideband envelope velocity measurement to solve the phase ambiguity in the phase-derived method,thereby obtaining a high-precision velocity estimation value for highspeed targets.Simulation analysis verifies that the algorithm has centimeter-level root-meansquare error of velocity measurement when the SNR is above 20 dB,which is of great significance to the research of high-precision target detection.Then,this paper presents the overall realization plan of the high-speed target detection signal processor,including the frame structure design,the software and hardware platform design,and the task assignment of the system.Mainly expounds the work of the signal processor DSP board in high-speed data transmission,and real-time signal processing based on the master-slave model.Finally,this article has conducted a performance test on the high-speed target detection signal processor.The test results show that the radar system can complete the high-precision detection task of high-speed targets.