Composite Scattering Of Rough Sea Surface And Target Based On Hybrid Method

The research on target's scattering characteristics in complex background,especially the scattering characteristics of the composite model of target and rough sea surface,has important research value and wide application in the fields of microwave remote sensing,target recognition and radar imaging.More and more engineering applications make a high demand for the accurate and effective analysis of the electromagnetic scattering problem of the composite model with the target and rough sea surface.In this paper,the hybrid method which combined the numerical method with the high frequency approximation method are used to deal with the composite scattering characteristics of rough sea surface and target,which provides valuable reference for practical engineering application.The following is the main research content of this paper:First,this paper introduces several sea spectral models and how to generate the rough sea surface.Considering the fact that the numerical method is difficult to deal with the electrically large rough sea surface,so the scattering characteristics of rough sea surface are analyzed by physical optics method that is modified by using the equivalent edge current method.The results show that the modified physical optics method has a significant improvement in precision,and the efficiency of the approximate method in calculating the electrically large rough sea surface has been proved.At the same time,the influence of the variation of control parameters of sea surface on scattering coefficients is studied.Then,based on the surface integral equation of the perfect conductor,this paper introduces the basic principle of MoM which is the solver of the integral equation,and also introduces the RWG basis function and the selection of test function.Then the MLFMA is studied,including the principle of MLFMA and the solution steps are deduced in detail.The correctness of the algorithm and its applicability in practical application are verified by some examples.In order to calculate and analyze the complex scattering problem of rough sea surface and target,a hybrid method(numerical method+ approximation method)is used.This method combines the advantages of approximate method and numerical method.The "four-path" model is used to deal with the coupling between the rough sea surface and the target,which saves the computation time and the memory consumption to some extent,and verifies the correctness and applicability of the hybrid method by several representative examples.The influence of the target height and the different polarization modes on the electromagnetic scattering of the complex model is also studied.Finally,the principle and solving steps of the IE-DDM is introduced in detail,and the IE-DDM is accelerated by using MLFMA,then the method is applied to the calculation of complex scattering of rough sea surface and complex multi-scale target based on hybrid method,and a better calculation result is obtained.