PO-SBR Algorithm For Investigation On Composite Scattering And High Resolution Image From A Target Above Ground

The study of electromagnetic scattering of targets under complex environmental backgrounds has great significance and research value in theoretical calculations and engineering applications.With the rapid development of radar detection and target recognition technology,how to efficiently solve target and its electromagnetic scattering with complex background has become the focus of research by scholars at home and abroad.Based on the fine geometric model of the ground target,this thesis uses the SBR-PTD method to calculate the monostatic and bistatic RCS of the T90 tank,the Ratel armored vehicle,and the Sword UAV,and verify the algorithm results;The PO-SBR algorithm is used to establish a composite electromagnetic scattering model between the ground and the target,and the electromagnetic scattering characteristics of a single landform and a complex target above the two landforms are analyzed;The high-resolution imaging research of complex targets above the ground is carried out,and the position and number of peaks in the HRRP curve under different radar and target parameters and the change law of target contours in ISAR images are studied.The main work of the thesis including:1.Accurate geometric modeling of typical complex targets.The functional characteristics of commercial modeling and simulation software(FEKO,Rhinos)and the application instructions in the process of modeling are briefly introduced,and the possible problems in model reconstruction are summarized,and the corresponding solutions are given,and the fine geometric models of complex targets such as the T90 tank,the Ratel armored vehicle and the Sword UAV above the ground are established in turn,and according to the frequency of the incident wave,the geometric model of the complex target is divided into triangular plane elements to prepare for further electromagnetic scattering calculation.2.Research on electromagnetic scattering of complex targets based on SBR.Due to the complex structure and electrical large size of complex targets on the ground,and considering the multiple scattering of electromagnetic rays on complex targets,the thesis uses the SBR method combined with the PTD to establish the complex target and analyse the monostatic and bistatic RCS of complex target under different incident angles,azimuth angles,polarization modes,and compare them with the results calculated by the high-frequency algorithm in the professional simulation software FEKO,and verify the correctness of the SBR method in solving the complex target electromagnetic scattering problems.3.Research on electromagnetic scattering of complex targets above the ground based on PO-SBR.For the composite model of the actual ground and complex targets,the thesis adopts the hybrid method of PO method and SBR method to solve the problem.The main solution ideas are as follows: the direct scattering of the ground uses the PO method,and the direct scattering of the complex target uses the SBR method,and the coupling scattering is solved by ray tracing technology.The PO-SBR method is used to calculate the RCS of a simple target above the rough surface,by comparing with the MLFMM method in commercial software FEKO,and the correctness of the PO-SBR method is verified.Taking into account the diversity of ground types,the electromagnetic scattering characteristics of complex targets above a single landform and two landforms under different incident parameters are analyzed in detail.4.High-resolution image study of complex targets above the ground.The thesis introduces the basic principles of one-dimensional HRRP and Inverse Synthetic Aperture Radar(ISAR),based on the backward broadband radar echo data of complex targets above the ground,the inverse fast Fourier transform is used to obtain the high-resolution range image of the composite model,and then the changes in position and number of the peak in the one-dimensional range image of the composite model under different incident angles are analyzed.And based on the RD algorithm,two-dimensional high-resolution ISAR image simulation is performed on three types of complex targets: T90 tank,Ratel armored vehicle,and Sword UAV.