路面材料介电常数非均匀模型雷达电磁波模拟

Ground penetrating radar electromagnetic waves simulation of pavement model with pavement material′s inhomogeneous dielectric parameter

针对实际路面材料颗粒的随机分布特点以及离散颗粒对电磁波的散射事实,建立了半空间路面雷达电磁波一维时域有限差分(1D-FDTD)方程,实现了沥青路面材料均匀和非均匀介电常数两种模型的空气耦合天线雷达电磁波正演模拟,并对以上两种模拟波与实测波形进行了对比分析.结果表明:路面材料的非均匀介电常数模型更加符合工程实际,为路面雷达进一步精确检测厚度及其他应用提供了新的方法.

According to random distribution characteristics of practical pavement particles and scattering of dispersed particles on electromagnetic wave, the one-dimension finite difference time domain （1D-FDTD） equations of ground penetrating radar （GPR） electromagnetic wave, which propagates in half-space, are briefly established. And the electromagnetic wave of the air-coupled antenna GPR which propagates in asphalt pavement with surface material＇s homogeneous or inhomogeneous dielectric parameter are all forward simulated. Then the comparisons between the two models simulation waves and actual measurement wave are analyzed. It is concluded that the first model with the surface material＇s dielectric parameter selected on random can inoseulate the actual measurement wave and well correspond to the reality. The research is helpful for GPR backward simulation as measuring thickness and other applications.