Research On Three-dimensional Perspective Imaging Technology Of Through-the-wall Radar

The three-dimensional imaging technology of through-the-wall radar utilizes electromagnetic waves to see through wall and can access the information of the hidden target.Compared with the traditional through-the-wall radar,this technology can not only get the target position and respiratory frequency,but also obtain important information such as target contour and posture.It has become a hot research topic in the world.This thesis studies imaging methods,array design,interference suppression,three-dimensional reconstruction,etc.The main research contents include:1.Aiming at the typical application scenarios,a three-dimensional electromagnetic wave propagation model is established,and two related imaging algorithms based on MIMO array for ultra-wideband through-wall radar are studied.This paper also analyzes the effect of array parameters on imaging results,and studies the non-uniform array based on Fermat rules for the grating lobe problem.Electromagnetic simulation results verify that the array is significantly better than the traditional array.2.In view of the interference problems in the practical application,two effective interference suppression methods are studied.The method based on the phase coherence factor mainly uses the phase difference between echo channels to weight each pixel point.This method has obvious interference suppression effect when the SNR is high.Another method based on empirical mode decomposition is more direct.This method extracts the target information from the raw echo and discards the clutter component,which can effectively improve the imaging quality under low SNR conditions.3.For the problems of large size and high cost of traditional through-wall imaging radar,combined with the hot WIFI and UAV technology,used the experience of mature computed tomography imaging technology,a 3D scene reconstruction scheme is designed.The scheme can make the radar portable and cost-effective,and broaden the thinking for the three-dimensional imaging technology of the TWR.Both the experiment and simulation results prove the feasibility of this scheme.