Modeling of Multilayered Media Green’s Functions With Rough Interfaces
Modeling of Multilayered Media Green’s Functions With Rough Interfaces
复制标题
DOI：
10.1109/tgrs.2019.2915676
复制
发表时间：
2019-10
影响因子：
8.2
通讯作者：
F. Jonard;F. André;N. Pinel;Craig Warren;H. Vereecken;S. Lambot
中科院分区：
文献类型：
--
作者：
F. Jonard;F. André;N. Pinel;Craig Warren;H. Vereecken;S. Lambot
水平分层介质通常用于表示天然存在的和人造的结构，例如土壤、道路和路面，当由探地雷达（GPR）探测时。电磁波在这种多层介质中的散射依赖于界面的粗糙度。本文在标量Kirchhoff切平面近似（SKA）模型的基础上，结合平面多层介质绿色函数，建立了一种考虑随机粗糙层的封闭形式的渐近电磁模型。为了验证我们的扩展SKA模型，我们进行了模拟，使用基于时域有限差分（FDTD）方法的数值EM求解器。我们建立了一个三层介质模型，一个由两层不同材料组成的粗糙界面覆盖的完美电导体（PEC）基层。在第一和第二界面处的反射都很好地再现了SKA模型的每个粗糙度条件。对于PEC表面的反射，扩展的SKA模型略微高估了反射，并且这种高估随着粗糙度的增加而增加。FDTD模拟输入值和顶部界面的反均方根（RMS）高度估计值之间也取得了良好的一致性，而第二界面的反均方根高度略高估。我们的渐近正演模型的准确性和性能表明，模拟粗糙的多层介质，因此，GPR数据的全波形反演非侵入性表征土壤和材料的前景看好。
Horizontally stratified media are commonly used to represent naturally occurring and man-made structures, such as soils, roads, and pavements, when probed by ground-penetrating radar (GPR). Electromagnetic (EM) wave scattering from such multilayered media is dependent on the roughness of the interfaces. In this paper, we developed a closed-form asymptotic EM model considering random rough layers based on the scalar Kirchhoff-tangent plane approximation (SKA) model that we combined with planar multilayered media Green’s functions. In order to validate our extended SKA model, we conducted simulations using a numerical EM solver based on the finite-difference time-domain (FDTD) method. We modeled a medium with three layers—a base layer of perfect electric conductor (PEC) overlaid by two layers of different materials with rough interfaces. The reflections at the first and at the second interface were both well reproduced by the SKA model for each roughness condition. For the reflection at the PEC surface, the extended SKA model slightly overestimated the reflection, and this overestimation increased with the roughness amplitude. Good agreement was also obtained between the FDTD simulation input values and the inverted root mean square (rms) height estimates of the top interface, while the inverted rms heights of the second interface were slightly overestimated. The accuracy and the performances of our asymptotic forward model demonstrate the promising perspectives for simulating rough multilayered media and, hence, for the full waveform inversion of GPR data to noninvasively characterize soils and materials.