The Research On The Simulation Of Ground-penetrating Radar

With the development of electromagnetic applications in modern science and technology, electromagnetic wave surveying underground targets become an important area of application. As the close relationship between the Earth's surface and human life, Transmission and reflection of electromagnetic waves more complex in the ground surface medium than in the free space. Therefore, ground penetrating radar (GPR) which of advantages of high resolution and high efficiency has become more popular for detection methods of engineering and geophysical in recent years. As overseas technique is much more early and more advanced than our own country, But the domestic scientific research units has also made great progress in the study of GPR on the full basis of referring to foreign technology. Making use of numerical model to simulate the complex electromagnetic characteristics of model ground-penetrating radar which is a major element of theoretical research. Since mass media is so complex that the requirements of the numerical simulation of stability and high accuracy is very high, so many new issues need to be resolved.This paper may be divided into three parts:at first, This article introduces the principle of ground penetrating radar and research significance, and makes a brief introduction about the development status and research methods of ground penetrating radar in recent years. in the next place, the basic theory of the traditional FDTD method and High-Order FDTD method were introduced and compared in detail. For the introduction of the numerical method, it provides a good theoretical basis and technical support. Combined with the characteristics of GPR pulse propagation, the complex coordinate variables and recursive convolution technique perfectly matched layer absorbing boundary condition are introduced to improve the total field boundary condition, the convolution absorbing boundary conditions (CPML)example is discussed and realized in this thesis. At last, using the methods Combined with high-order FDTD method and convolution perfectly matched layer absorbing boundary conditions,this paper simulates the examples of the Surface-based reflection GPR and cross hole and vertical radar profiling (VRP).Numerical results of this article show that this thesis can get much more precise Observation that Different electrical parameters in Layered media exercises a great influence on the Propagation of electromagnetic waves.In a word, the research in this thesis not only get more accurately Forward radar cross section of the electromagnetic waves propagation in layered medium, but also simplify the calculation,improve the computational efficiency.