Analysis Of Scattering Characteristics Of Electrically Large Targets Based On TDSBR And TDEEC Algorithms

The electromagnetic calculation of electrical large-size targets has always been one of the leading research topics in the electromagnetic field,what's more,with the application of microwave and millimeter-wave radars in engineering,the research has been paid more and more attention to on the electromagnetic scattering characteristics of electrical large-size targets.The high-frequency method treats each surface element as an independent scattering center when certain assumptions are met,which greatly simplifies the calculation process,and therefore it's widely used in electromagnetic scattering calculation of electrical largesize targets.The time-domain shooting and bouncing ray algorithm is a typical highfrequency method,which first discretizes a large number of ray tubes,and then tracks the ray tubes and judges the intersection with the facets of target,and finally integrates the intersecting ray tubes with analytical physical optics method to obtain the scattering field.However,for the complex targets with many edges,the diffraction field generated by the edges cannot be ignored.In this paper,the scattering and diffraction fields of complex targets are calculated by the time-domain shooting and bouncing ray algorithm based on the timedomain equivalent edge current method,and furthermore,multiple sets of examples are compared to analyze the scattering characteristics of targets.The main research of this article is as follows:Firstly,the method of modeling and meshing using Hypermesh is briefly introduced,and a way of edge extraction is proposed.In addition,to verify the effectiveness and correctness of this way,it is used to extract edges from satellite,drone,and ship models.Secondly,after assuming that a certain line current or line magnetic current exists in edges,the expressions of the line current and the line magnetic current are derived,and then the diffraction coefficient related to the diffraction angle is calculated to obtain the expression of the diffraction field.Then,the radar cross section calculated by the time-domain shooting and bouncing ray algorithm modified by the time-domain equivalent edge current method and analytical solution are compared to verify the correctness of the algorithm.Finally,the dynamic current distribution of the tanker,satellite and drone models under the incidence of differential Gaussian pulses are calculated,and far fields and radar cross sections of the typical air single target,air target queue,ground single target and ground target queue are calculated at different incident angles using the time domain shooting and bouncing ray algorithm modified by the time domain equivalent edge current method.Besides,rough surface modeling to the ground target queue is added to make it closer to the actual environment,and its far-fields and radar cross sections are calculated,and then the influences of the environment on its electromagnetic characteristics are compared and analyzed.