在采矿或开凿隧道之前,迫切需要一个好的方法来探查地下地质条件.传统的地球物理方法包括重力、磁力、电阻率、激发极化和电磁感应技术,用于井下已有某些成果.但是由于这些方法取决于电位场的微小畸变,自然在探查范围的分辨能力方面是有限的.为了得到较高的分辩能力和探测距离的比,从原理上讲,可以利用辐射作为探查手段.已知能够穿透岩石的辐射有四种类型:中子、硬宇宙射线、地震波和电磁波.头两种不容易控制.地震波早就用于勘探石油,但是井下地震法的发展尚处在初期阶段.在电性上有显著变化的物体或界面能反射电磁波.地表面的土壤由于导电率很高,对于雷达来说是不透明的,可是其下的许多岩石, There is an urgent need for a good method to explore subsurface geological conditions before mining or tunneling.Traditional geophysical methods include gravity, magnetism, resistivity, induced polarization, and electromagnetic induction techniques that have been used for some of the downhole results. Since these methods depend on the small distortion of the potential field, they are naturally limited in their ability to detect range resolution. In principle, radiation can be used as a probe in order to obtain a higher resolution and detection range ratio There are four types of radiation that can penetrate rocks: neutrons, hard cosmic rays, seismic waves, and electromagnetic waves. The first two are not easily controlled. Seismic waves have long been used to prospect oil, but the development of downhole seismic methods is still in its infancy. Electrically significant objects or interfaces can reflect electromagnetic waves. The surface soil is opaque to radar because of its high conductivity, but many of the rocks beneath it,