Simulation Study Of Microwave Through-the-Wall Imaging

Through-The-Wall Radar plays a vital role in military,counter-terrorism,post-disaster rescue and security inspection.Simulation study of through-the-wall imaging is helpful to understand the theoretical knowledge of through-the-wall imaging and facilitates the processing of echo and the imaging of target.Use CST Microwave Studio software to establish single transmission,single receiving and dispatch through-the-wall imaging simulation model in this paper.Set up the relevant simulation conditions to obtain echo,analyse influence factors of echo and preprocess echo.Use reverse projection imaging algorithm to simulate single and multipoint targets imaging and analyse target imaging.Mainly completed the following points:1.This part introduces basic theory of through-the-wall imaging and analyses the composition of echo signal and the choice of detection signal.Elaborate the influence of wall on propagation speed and propagation path of detection signal in detail.These lay the theoretical foundation for analysis and preprocessing of echo signal and imaging of target point in the later.2.The construction and simulation of through-the-wall imaging simulation model.This part mainly includes the design of Vivaldi antenna,the addition of wall model and single metal ball for detection target,the introduction of receiving and transmission antenna,the related settings of simulation conditions and the addition of antenna excitation signal.The model is simulated and echoes are obtained at each location.3.Based on simulation model of through-the-wall imaging,the influence of relative dielectric constant of wall,the distance between antenna and wall,the antenna in different directions and the target in different directions on waveform are analysed by simulation.The background elimination method is used to preprocess echo to remove the clutter.4.According to the principle of reverse projection imaging algorithm,the single point target and multipoint target imaging are processed.And use the shortest time method to calculate the target echo delay.The effect of gate flap in imaging is suppressed by means of threshold processing.The effect of number of antenna distribution and number of mesh division on the quality of imaging is analysed.