Studying The Dispersion From Heterogeneous Underground Materials In Ground Penetration Radar

For data processing and interpretation on Ground Penetration Radar (GPR) measurements, it is always supposed that the underground materials are homogeneous isotropic medium. However, the most underground materials are heterogeneous due to the complex composition of minerals, infrastructure in nature, or with variation porosity and water moisture filling in the pore space. The heterogeneity of underground materials may vary the traveling characteristic of the electromagnetic waves. This thesis, titled in "Studying the Dispersion from Heterogeneous Underground Materials in Ground Penetration Radar", focus on the correlation between the variance of the underground materials in dielectric property, conductivity, porosity, or water moisture and the traveling characteristic of the radar waves by means of the numerical and physical modeling technologies. The main results of the study is as below: 1. A program was developed to model 3D GPR responses using finite difference time domain method. Instead of the commercial or free program widely used today, it can be used to modeling the heterogeneity of underground materials so as to provide a perfect tool for studying the dispersion from heterogeneous underground materials in Ground Penetration Radar. 2. Numerical modeling technology, for the first time, was used to study the correlation between the variance of the underground materials in dielectric property, conductivity, porosity, or water moisture and the features of GPR signals. The usability of the numerical modeling technology for studying the materials dispersion was proved by comparing the numerical modeling results with the physical modeling results. 3. Based on the forwarding results, â‘ it was discussed that the heterogeneity of medium is how to increase the 'noise'level and how to influence the feature of GPR signals under the condition that the random noises with normal distribution, zero...