不同地下介质条件下探地雷达的探测深度问题分析

探地雷达技术巳成为近年来岩土工程领域探查地下目标体的重要手段，其应用的关键问题之一是如何准确计算不同介质条件下的探测深度，并确定探查对象是否在雷达探测系统的有效测距范围之内。根据探地雷达测距的基本公式，讨论了雷达测深的重要影响因素：反射目标体的反向散射增益及散射截面积。将地下岩土介质的反射体目标模型归结为三种典型类别：光滑、粗糙反射界面及点状目标体，同时给出了这三种反射体的简单数学模型，及计算分析。结合目前国内广泛使用的三种不同类型的探地雷达系统，计算得到了在不同地区或不同地下介质条件下的最大探测深度，为实际探测工程提供了较有价值的参考。

The analysis of detectable range of ground-penetrating-radar system in different underground medium

The ground-penetrating-radar (GPR) technology has now become an important means for detecting and locating underground objects in geo-technical field. One of the main important problems is how to exactly compute the detection depth in different underground medium, and confirm whether the objects is in the detectable range of the GPR systems or not. According to the GPR range equation, the major factors including scattering cross-section and backscatter gain of target are discussed in this paper. The model of underground geo-technical medium can be come down to three types, smooth plane reflector, rough plane reflector and point target. The simple mathematics models of these reflectors are prsented. Combined with the different GPR systems being widely used in geo-technical field, their maximum detectable ranges are computed in different area or underground medium, and the results can provide useful reference for detection and location of objects.