基于CPML边界条件的水下地质雷达数值模拟

Numerical Simulation of Underwater Geological Radar Based on CPML Boundary Condition

水下的地质雷达探测与常规的地质雷达探测具有显著的不同点。文中对CPML吸收边界条件的公式进行推导,并通过数值模拟对均匀介质以及非均匀介质中吸收边界条件的吸收效果进行了验证,数值模拟的波场快照证明了CPML吸收边界条件在水下的地质雷达数值模拟中具有很好的吸收效果。通过对水平层状介质模型以及倾斜层状介质模型开展数值模拟,并结合实际探测的雷达图像,证明地质雷达对于水下地层的探测能够取得良好的效果;通过对空洞体位于不同深度时的数值模拟,证明了地质雷达对于水下的空洞探测也能对其位置及规模进行较为准确的判断。这为水下地质灾害的探测提供了理论依据及指导。

There are significant differences between the GPR detection and the conventional GPR detection. The formula of absorption boundary conditions on CPML has been derived in this paper, and the homogeneous and non absorption effect of absorbing boundary conditions in homogeneous medium have been veri- fied by numerical simulation. It is proved that the numerical simulation of the wave field snapshot has good absorption effect in numerical simulation of GPR. Based on the horizontal layered medium model and inclined layered medium model, the numerical simulation is carried out. Combining with actual radar image detection, it is showed that geological radar can achieve good results in the detection of subsurface aquifers. Based on the numerical simulation of hole bodies at different depths, it is proved that geological radar can achieve more accurate judgment on its location and size for detecting strata under water. It provides a theoretical basis and guidance for the detection of underwater geological disasters.