中文摘要：

通过建立探地雷达波振幅与土壤介电常数之间的定量关系可反演土壤含水量.在采用时间域有限差分法建立土壤分层模型的基础上,模拟探地雷达电磁波在均匀分层土壤介质中的传播特性,分析土壤介电常数与雷达回波振幅之间的变化规律,证实了回波振幅随着介电常数的增大而减小,总结出介电常数与振幅之间的幂函数关系式.最后通过室内土壤模型对此关系式进行了验证,结果表明由此关系式反演出的土壤含水量值与土壤三参数仪测定的含水量值相一致.

英文摘要：

Water content in soil can be derived from the relation between changes in ground penetrating radar signals and the soil＇s dielectric constant. Using the finite difference time domain（FDTD） method, a model of layered soil is established to simulate ground penetrating radar electromagnetic waves in the soil. The transmission characteristics of layered soil are analyzed using the model. The results indicate that a functional relation exists between the soil dielectric constant and the amplitude, i.e., the wave amplitude decreases with the increased electric constant. With an indoor soil model, the obtained relationship is verified： the computed water content agrees with the wet sensor data.