The Study Of Electromagnetic Scattering Characteristics Of High-speed Moving Objects

The study of electromagnetic scattering characteristics of ultra-high-speed moving objects has very important value in various fields such as national defense-science and technology,and military,and has become one of the objects of great development of contemporary world powers.Various methods have been proposed to study this subject so far.For example,the finite element method is combined with the Lorentz transformation;the time domain finite difference method is combined with the Lorentz transformation.However,no one uses the method of moments to study the subject.As one of the more mature classical algorithms,the moment method has its own unique advantages in electromagnetic scattering calculation.First,the method of moments only needs to discretize the surface of the scatterer or the space occupied by the scatterer.Second,the radiation condition can be automatically satisfied by the Green's function in the integral equation,and no additional consideration is needed for the absorbing boundary condition.In this thesis,based on the moment method and Lorentz transformation,the electromagnetic scattering characteristics of ultra-high speed moving targets are studied.The main research steps are:firstly use the relative theory to transform the moving square shape,and transform the incident wave under the experimental system coordinates into the stationary system;then use the moment method to calculate the surface current of the conductor or dielectric body in the stationary system.And surface magnetic current;the near-far field transform is used to obtain the scattered field in the far field region.Finally,the scattering field is transformed back to the experimental system.First of all,this thesis briefly introduces the basic knowledge of the moment method,the basis of the basis function and the test function,and the basic steps of solving the general electromagnetic field problem by the moment method.Secondly,based on the basic formula of Lorentz transformation,the Lorentz transformation of the incident parameters of TM wave and TE wave under different reference frames is derived.Lorentz transformation of scattering parameters.The Doppler effect is derived from the relationship between the derived scattering angle frequency and the incident angular frequency.The Doppler effect of incident waves at different angles is given by simulation software and analyzed.Finally,the surface current of the high-speed moving target is obtained by the moment of method,and then the double-station scattering width under the incident of the TM wave and the TE wave is obtained,and the conclusion is obtained by comparing the different speeds.The calculation results show that the influence of different motion speeds on the target radar scattering and Doppler effect can not be ignored.The Doppler effect is related to the incident angle,the target moving velocity,and the scattering angle,and is symmetrical about the target moving direction.