The Application Of The Physical Optics Method In Electromagnetic Scattering Of Electrically Large Targets

The solution of Radar Cross Section(RCS)for high-frequency large-size complex targets is an extremely challenging and important issue recent year,especially for the problem of solving target RCS under terahertz electromagnetic wave irradiation.This topic involves a wide range of research methods.Among them,the Physical Optics(PO)algorithm is recognized as having excellent applicability in the field of high-frequency electromagnetic field calculations,and it can give satisfactory results especially for the scattering and radiation problems of large-size targets.The advantages of speed,small memory,etc.also make it popular with the majority of scholars.For PO algorithm,occlusion judgment is a big difficulty of PO algorithm.This paper proposes a new occlusion judgment algorithm for solving the problem of occlusion judgment algorithm of traditional PO algorithm,so as to reduce the memory consumption of the program and reduce the running time of the running program when solving the radar cross section problem of high-frequency large-size complex targets.First of all,this paper briefly introduces the basic theory of the moment method.The moment method is a classical method in computational electromagnetics.It has important guiding significance to understand the principle and implementation process of the moment method.In this paper,taking the Electric Field Integral Equation(EFIE)as an example,the process of pushing each step of the Method of Moments(MOM)is given in detail.Taking the method of moments as an example,the computational electromagnetics is briefly introduced.The basic steps of the numerical algorithm to solve the target scattering problem.Secondly,this article focuses on introducing the physical optics algorithm,the two major difficulties for solving the problem of the physical optics algorithm-integral discretization and occlusion judgement.This paper gives a detailed introduction.For the occlusion judgment,this paper gives a simple and practical occlusion judgment algorithm,and for the integral discretization,this paper gives three kinds of integral discretization methods-direct discretization,Gaussian integral discretization and Gordon integral to discretize the integral equation.processing,introduce the Gordon integral discrete,detailing how to use the Gordon integral to the area of a triangle is divided into integral triangle along the side of the line,finally using metal plates,dihedral models,cube models,boat models F117 aircraft model to prove the accuracy of the algorithm.Finally,this paper proposes a new occlusion judgment algorithm for occlusion judgment problem in PO algorithm.A new shading judging algorithm was applied to the terahertz field,and the radar cross section(RCS)of the slab,column vertebral body and boat under the terahertz wave was successfully obtained.