| This dissertation presents the systematic research about electromagnetic (EM) scattering from the rough surface and the composite electromagnetic scattering from the rough surface and the targets, which mainly includes:researching the one-dimensional rough surface EM scattering using the high order integral small peraturation method; the modified two scale method(TSM) combined with the VRT (vector radiative transfer) and Mie theory for EM scattering from the wind driven two-dimensional rough surface with foam layer covering; the EPILE(extend propagation inside layer expansion) combined with the GFBM(generalized forward-backward iterative method) for composite scattering from one-dimensional conducting rough surface and the targets above and on; the EPILE combined with FBM(forward-backward iterative method) for composite scattering from one-dimensional dielectric rough surface and conducting targets above and below; the EPILE combined with FBM for composite scattering from one-dimensional dielectric rough surface and dielectric targets above and below; the EM scattering from two-dimensional rough surface, three dimensional target and the EM software simulations for composite scattering from two-dimensional rough surface and the three-dimensional target. Emphasis is put on studying the EM scattering from the single random rough surface, the composite EM scattering from the two-dimensional targets above and on the one-dimensional rough surface, the composite EM scattering from the two-dimensional targets above and below the one-dimensional rough surface and the composite EM scattering from the three-dimensional target above the two-dimensional rough surface. The main works are as follows:1. Modeling the one-dimensional rough surface, the high order scattering coefficient of the high order small peraturation method is derived, for the slight rough surface with finite length, the tapered-plane wave is applied, the edge effect of traditional plane wave is conquered, through comparing the numerical results by this method with those by the method of moments(MOM), the exactness and efficiency of this method is verified.2. For the wind driven two-dimensional dielectric rough surface with foam layer covering EM scattering problem, the modified TSM(MTSM) combined with the VRT and the Mie are applied. The MTSM is used to calculate the single rough sea surface more exactly, the VRT and the Mie theory are applied to calculate the local scattering of the foam particles and the foam-sea surface coupling reactions, the validity of this scheme is verified by comparing with the relevant experimental data, meanwhile, the results of different incident angles, different scattering angles, different frequency, different azimuth angle and different polarization are given and discussed in detail.3. The EPILE combined with the GFBM for fast calculating the composite scattering from one-dimensional conducting rough surface with targets above and on is presented, the EPILE is applied to accelerate the coupling reactions between the target above and the undyling surface, the GFBM is applied to accelerate calculation the local interaction from the rough surface with floating target. The numerical results not only include the composite scattering from the Gaussian rough surface and the cylinder, but also include the composite scattering from the rough sea surface with missile-like target above and the ship-like target floating, the exactness and efficiency of the method is verified by comparing with the MOM, the complexity can be decreased and the efficiency can be improved by this method under the promise of enough exactness.4. The EPILE combined with FBM for composite scattering from one-dimensional dielectric rough surface and the two-dimeisional conducting targets both above and below are presented. The EPILE is applied to accelerate the'rough surface- conducting target above'and'rough surface-conducting target below' coupling reactions, the FBM is applied to accelerate the dielectric rough surface local interaction, the Gaussian rough surface and the cylinder targets above and below are chosen as example, comparing with the MOM, the complexity can be decreased and the efficiency can be improved under the promise of enough exactness by this method.5. The EPILE combined with FBM for composite scattering from one-dimensional dielectric rough surface and the two-dimensional dielectric targets both above and below are presented. The EPILE is applied to accelerate the'rough surface- dielectric target above'and'rough surface-dielectric target below' coupling scattering, the FBM is applied to accelerate the dielectric rough surface local scattering, the numerical results not only include the Gaussican dielectric rough surface and the simple dielectric cylinders of small size, but also include the PM dielectric sea surface and the more complex dielectric missile-like and ship-like targets of bigger size, the complexity can be decreased and the exactness can be improved by this method under the promise of enough exactness by comparing with the MOM, the bigger of the size and the more complex of the shape of the targets are, the advantage of this method in efficiency is more evident.6. For numerical investigating the EM scattering from two-dimensional rough surface or three-dimensional target, the Delaunay algorithm is applied to construct the triangular grid models of the rough surface or target. Basing on the RWG baisis-MOM, the dipole model is introduced to calculate the scattering field and the scattering cross section, the results are verified by comparing with that of the traditional RWG baisis-MOM and the FEKO EM software. Further modeling the composite model of two-dimensional rough surface-three-dimensional target and calculating the composite scattering using the FEKO EM software. For the case that the calculating memory requirement exceeds the memory limitation of the computer which is caused by the larger size of the rough surface or target, the out of core-parallel technology of the FEKO software is applied to accomplish the 2-D rough surface-3-D target composite EM scattering calculation.
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