探地雷达的时域仿真方法研究

The Research on the Simulation of Ground-penetrating Radar

探地雷达(GPR)是近些年来比较流行的一种工程和地球物理探测方法。利用数值模型来模拟复杂的地下电磁特性模型是探地雷达理论研究的主要内容之一。论文利用复坐标延伸变量和递归卷积技术的完全匹配层吸收边界条件,构造了模拟基于表面反射GPR模型和垂直探测雷达(VRP)模型的高阶时域有限差分方法(FDTD);并对该方法的稳定性条件进行了理论和数值实例的分析。根据典型探地雷达模型仿真的正演剖面图,可观察到电磁波在地下分层介质中的传播规律,以及电特性参数对电磁波传播的影响。

Ground Penetrating Radar(GPR) is a detection method of project and geophysics that is getting more and more popular in recent years.Numerical model is used to simulate the complex underground electromagnetic characteristics that are one of the main contents of the theoretical study of model of ground-penetrating radar.The paper adopts the complex stretched coordinated space and uses the recursive convolution PML(CPML) technique to construct the high order finite difference time domain(FDTD) method for simulation of surface-based reflection GPR and vertical radar profiling(VRP) model.The stability of the method is also analyzed with theory and numerical results.According to the forward simulation profile of the typical penetrating radar model,we obtained the law of the electromagnetic wave propagation and the impacts of different permittivity and conductivity in layered media.