Design And Signal Processing Of Networked Radar Near-field Detection System

Networked radar has become a research hotspot in the field of radar due to its excellent characteristics such as high Angle resolution,strong mobility,good antijamming ability and strong expansion ability.Due to the wide area distribution of networked radar,the target near-field effect is relatively serious.If the far-field array receiving signal model continues to be used,the effect of synthesis processing will decline or even fail.Therefore,this thesis will study the synthesis of networked radar receiving signals based on the near-field array receiving signal model.In order to solve the problems of multi-gate and high side lobe caused by the uniform and sparse arrangement of nodes in networked radar,this thesis studies the node position optimization algorithm to suppress the gate lobe and reduce the peak side lobe level.Finally,based on the above research,this thesis completes the networked radar target detection simulation design.This thesis specifically studies and analyzes the following aspects:(1)Under the hypothesis of near-field spherical wave,the receiving signal model of near-field array is deduced.Based on the received signal model of the near field array,the coherent conditions of the target echo are analyzed,including the coherent conditions of the target,the consistency of the Doppler element,and the consistency of the range element.Aiming at the problem of inconsistency of range units for multi-path near-field targets,a combined space-range search algorithm is presented,and the feasibility of the algorithm is discussed and analyzed.(2)Study the difference between near field and far field array received signal models;The influence of time and phase synchronization error on the synthesis performance of networked radar is analyzed.Based on the near-field array received signal model and the space-distance joint search synthesis algorithm,the node position error and channel inconsistency error are analyzed.Considering that there may be target mismatch in the processing process,the synthesis performance of the system is discussed and analyzed in the case of target mismatch in range and angle respectively.(3)Study the networked radar array method,compare and analyze the non-uniform array,random sparse array,and the joint pattern performance of the random sparse array optimized by genetic algorithm.(4)The overall framework of networked radar target detection system is constructed,the signal processing flow of simulation scheme is introduced,and the signal processing sub-module is modeled and analyzed;The effectiveness of the whole near field detection system is verified for different target environments.