Multistatic Ground-based Radar Vehicle Targets Imaging And Micromotion Research

Multistatic ground-based radar system is the development trend of ground-based reconnaissance radar system in the future as it can not only increase the breadth and efficiency of obtaining battlefield information,but also have high flexibility,concealment and survivability,so as to provide a strong information support for having the battlefield situation under control.The vehicle target,as a typical representative target of ground moving targets,is one of the main concerns of ground-based reconnaissance radar.Based on the multistatic ground-based radar system,this paper focuses on the research of vehicle target imaging and micro-motion characteristics,and puts forward corresponding solutions for a series of problems and validates the feasibility and effectiveness of these methods.The main work of this paper is as follows:1.A signal model of ISAR(Inverse Synthetic Aperture Radar)imaging under bistatic radar system is established,and the imaging is processed by Back Projection(BP)algorithm.Firstly,the signal processing flow in the Dechirp receiving system is deduced to yearn the range compressed signal.Because the detection range of ground-based radar imaging is in the near-field of radar,it is not suitable to use far-field algorithm such as Range-Doppler(RD)algorithm.As a result of near range detection,BP algorithm does not produce large amount of computation and has good imaging effect.Therefore,the simulation of bistatic BP imaging is carried out for different moving states of the target,which verifies the feasibility and effectiveness of the algorithm in bistatic ISAR imaging.2.Based on the bistatic imaging,the method of image fusion is introduced.The advantage of the multistatic radar system is that the azimuth information of the target can be obtained more comprehensively,and the imaging result of different bistatic units can be fused to obtain a higher resolution imaging and more scatter information.In this paper,different image fusion methods,including coherent superposition,non-coherent superposition and bandwidth interpolation,are proposed according to the difference of radar station and target motion trajectory.The effectiveness of several methods is then verified by simulation.3.Based on the multistatic system,the micro-Doppler feature analysis of rotating wheels on the vehicle target is carried out.Firstly,the signal model of wheel target rotation is set up,and the results are then extended to multistatic situation.Finally,the rotation target is simulated by time-frequency analysis method,and the characteristics of vehicle wheel under different motion states are extracted to provide more comprehensive information for target recognization.