Computation Of Electromagnetic Scatterin From Rough Surface

Research on electromagnetic scattering of lunar surface becomes more and moreimportant in our "Chang-E" program development planning, which can verify measuredresults by radiometer. At the present time, the world's powerful countries are movingforward into deep-space exploration. The radiometer will be more carried on by spaceprobe for measuring radiation characteristics of the target area. The model can be used byextension in this case.Papers relied on the "national863" major project establishelectromagnetic scattering model of the lunar soil and caculated by FDTD (Finite-DifferentTime-Domain) method in computational electrodynamics. The results are compared withthe measured results.Currently, for electrically large rough surface scattring problem, the approximatemethods such as the perturbation method etc. are always taken to calculate the scatteringcoefficient. The obvious advantage is the calculation speed. But for the perspective of theresearch, calculation accuracy is the most important, so that the results of the theoreticalresults can guarantee to the measured results. The papers explain the application of theFDTD method in electromagnetic scattering of lunar three-dimensional multi-layer roughsurface from simple model to complex model analysis.In the study, the first chapter of the thesis describes the domestic and internationalresearch trends of the electromagnetic field numerical method. The second chapter detailsthe one-dimensional rough surface of two-dimensional FDTD method calculation process,including the basic theory of FDTD, the incident wave loading, connection boundaryconditions, absorbing boundary conditions, output boundary conditions. Comparations ofthe numerical simulation results of the rough surfaces with the different rms height aregiven. Comparations between rough surfaces with no object and with PEC (or dielectric)object are also given. The third chapter details the two-dimensional rough surface ofthree-dimensional FDTD method calculation, similarly to the one-dimensional roughsurface. Comparations between different rough surfaces with different rms height and with different materials are proposed. Chapter IV focuses on the parameters of lunar soilproperties including density, dielectric constant, iron and titanium content, water icecontent, and establishing a multi-dimensional lunar soil FDTD electromagnetic scatteringfrom rough surface computational model. The brightness temperature obtained with theperturbation method and the FDTD method has the same changing trend as the roughnessof rough surface changes. Chapter VI is a summary of the full paper.