Design And Implementation Of Multi-function Radar Signal Processing System

As an important part of multifunctional radar,the signal processing system is facing the challenges of complex detection environments,multiple tasks and diversified targets,which has become one of the most important research subjects at home and abroad.This paper mainly studies target detection algorithm suitable for different environments and target recognition algorithm based on micro-Doppler,completes the design of signal processing software based on localized hardware platform.Firstly,the basic theory of multifunctional radar signal processing is introduced.The clutter characteristics of low altitude and ground echo signals are analyzed,and the advantages and disadvantages of several clutter suppression methods such as MTI,AMTI and MTD are discussed.By comparing the detection performance of several constant false alarm detectors under different clutter backgrounds,it is found that VI-CFAR has better adaptability under complex clutter background.Based on the range dimension VI-CFAR,a multi-dimensional target detection technology is proposed,which judges the target by estimating the noise and clutter interference from the echo,thus ideally controls the false alarm probability of the radar.The conventional radar parameter measurement method is improved to promote the detection accuracy of radar.Then,the target recognition method based on micro-Doppler is studied.By establishing the UAV echo model,the modulation characteristics of the UAV rotor to the micro-Doppler frequency are analyzed.The time-frequency analysis technique is used to extract the micromotion characteristics of the rotor,and the influence of length,number and speed of the rotor blade on the micro-Doppler frequency is discussed.In view of the limitations of time-frequency analysis that requires high SNR and micro-motion signal strength,two signal decomposition algorithms,Chirplet and CEMD,are simulated and analyzed to realize the separation of airframe signal and micro-motion signal,and the micro-motion parameters of rotor blade are obtained through the "flicker" period of the remaining signals.Finally,according to the performance indexes and functional requirements of the signal system,the signal processing software designed based on the localized hardware platform.The feasibility of the radar signal processing system is proved by system test and field experiment.The radar not only completes the detection of low altitude targets and ground targets,but also has high detection accuracy.