Analysis Of Electromagnetic Scattering From Multi-layered Rough Surfaces Based On Physical Optics

Studying on electromagnetic(light)scattering from multi-layered rough surfaces has a significant impact on many aspects of the reality.Compared with the scattering from single-layered rough surface,the difficulties and key points of studying on scattering of the multi-layered rough surfaces lie on the mutual coupling of the rough surfaces.The electromagnetic scattering of multi-layered rough surfaces is mainly concentrated on in the passage,of which the main contributions are as follows:1.Based on the briefing of the basic theory of the PO method,the iterative process of the IPO's application to multi-layered rough surfaces is vividly explained,and the key formulations are derived to calculate the electromagnetic scattering from one-dimensional multi-layered rough surfaces.And then the method of IPO to specific one-dimensional gauss rough-surfaces is applied to calculate and analyze the bi-static radar cross section while the changes of roughness of the surfaces,the mean distance between the surfaces,and permittivity in different spaces respectively.At the same time,the applicability of the IPO method to one dimensional contaminated sea which is generated by PM sea spectrum and moderated by oil slicks is fully discussed and examined through comparing with the simulation results of MOM.2.Then IPO method is applied from one dimensional to two-dimensional multi-layered rough surfaces based on the same iterative method.Compared with one-dimensional algorithm,the different key formulations of two-dimensional are given.Furthmore the model of multi-layered rough surfaces is degenerated into two plane slabs,a model that the upper-surface is still rough-surface while the lower is the plane slab,and a model that the upper and lower surfaces are all rough surfaces.Based on these three different degenerated-models,the effect on bi-static RCS along with the changes of different parameters are calculated and analyzed.3.Due to the computational complexity of IPO method being very high which lead to low efficiency while calculating the large multi-layered rough-surfaces and the project we participate in during the scientific research,which is related to the scattering from multi-layered rough surfaces in the terahertz gap,that is why the revised reflection coefficients method is introduced to have a quick and approximate prediction about the RCS of scattering between rough-surfaces.Basically the revised-R method is investigated from the standpoint of physics and mathematics.And because of the existence of lossy media in the three spaces divided by two rough interfaces,the relevant questions of the complex refraction angle are discussed.Finally the revised-R method is used to calculate and analyze the impact on RCS along with the different parameters in the terahertz gap.