空气耦合探地雷达广泛用于地形条件差、地表障碍物较多的区域。为了精确评价地表障碍物位置对于空气耦合探地雷达探测的影响，将地表障碍物与探测物体水平方向上不同距离进行了量化研究。首先根据空气耦合探地雷达原理设计室内试验，通过室内实验对障碍物与探测物体不同距离展开研究，分析了障碍物对探测物埋深的影响，以及探测物体反射界面振幅的变化规律。然后通过正演模拟对相关规律进行验证。最后通过分析空气耦合探地雷达工作时电磁波传播规律，得出了振幅变化趋于平稳时，障碍物与探测物体间的距离与空气耦合探地雷达工作时各个参数的关系。研究结果表明：物理实验所用障碍物对空气耦合探地雷达探测地下物体时，探测埋深基本无影响；随着障碍物逐渐远离探测物体，探测物反射界面振幅会先增大然后趋于平稳。振幅增大阶段，振幅变化与障碍物的距离服从指数函数分布规律，振幅平稳阶段，振幅值与无障碍物时相当；将振幅刚好趋于平稳时障碍物与探测物体的距离定义为障碍物对振幅影响临界距离，天线悬空高度、探测物体的埋深、探测介质的介电常数、电磁波入射角都与临界距离有关。量化了地表障碍物对空气耦合探地雷达物理回波特性的影响，对空气耦合探地雷达工作具有指导意义。

Air-coupled ground penetrating radar is widely used in areas with poor terrain conditions and many surface obstructions. In order to precisely evaluate the influence of surface obstructions on the air-coupled ground penetrating radar detection, the horizontal distance between surface obstructions and the detection object was quantitatively studied. The air-coupled ground penetrating radar principle was first used to design an indoor experiment. The influence of the distance between the obstacle and the detection object on the depth of detection and the amplitude changes of the reflection interface of the detection object was analyzed. The relevant laws were then verified by forward simulation. Finally, the relationship between the distance between the obstacle and the detection object and the parameters of the air-coupled ground penetrating radar when it was working was derived based on the analysis of the electromagnetic wave propagation laws of the air-coupled ground penetrating radar. The research results show that the physical experiment obstacles used for air-coupled ground-penetrating radar detection of underground objects have no significant impact on the detection depth. As the obstacle gradually moves away from the detection object, the amplitude of the reflection interface of the detection object will first increase and then stabilize. The amplitude increase stage follows an exponential function distribution law, and the amplitude stability stage has the same amplitude value as when there are no obstacles. In this paper, the distance between the obstacle and the target object at which the amplitude is just approaching stability is defined as the critical distance at which the obstacle affects the amplitude of the radar signal. The height of the antenna, the depth of the target object, the dielectric constant of the detection medium, and the angle of incidence of the electromagnetic wave are all related to the critical distance. The result quantifies the influence of surface obstacles on the physical characteristics of the air-coupled ground penetrating radar and provides guidance for the operation of air-coupled ground penetrating radar.