天然平面电磁波在地下良导体界面上的反射与折射  

Reflection and Refraction of Natural Plane Electromagnetic Wave on the Interface of Underground Low Resistivity Body

作　　者：于熙 杨天春[1] 冯建新 付国红[1] 杨追 YU Xi;YANG Tianchun;FENG Jianxin;FU Guohong;YANG Zhui(School of Earth Sciences and Spatial Information Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Vocational College Engineering,Changsha 410151,China;Hunan Puqi Geological Exploration Equipment Research Institute,Changsha 410000,China)

机构地区：[1]湖南科技大学地球科学与空间信息工程学院,湖南湘潭411201 [2]湖南工程职业技术学院,湖南长沙410151 [3]湖南普奇地质勘探设备研究院,湖南长沙410000

出　　处：《矿业工程研究》2023年第3期53-58,共6页Mineral Engineering Research

基　　金：国家自然科学基金资助项目(51804112);湖南省自然资源厅科研资助项目(2021G12)。

摘　　要：当电磁波的波长小于地下地质体的尺寸时,电磁波会在地质体分界面上发生反射与折射,但现有文献未对这种反射与折射的矢量方向做统一规范化的表述.基于此问题,从理论层面分析探究平面电磁波在地下良导体界面上的反射与折射的传播规律及其传播方向.根据电磁波电场和磁场矢量的相互关系,从折射定律出发,结合天然电磁法在地表探测的实际应用情况,对地下良导体界面上电磁波的反射与折射问题进行理论推导与分析.研究发现:当天然电磁信号入射到地下良导体界面上时,折射波始终与入射波同相;而在TE模式时,反射信号E_(2)则与入射信号E_(0)反相,TM模式时反射信号H_(2)则与入射信号H_(0)同相.由此可确定天然电磁信号在地下电性分界面上的反射和折射的矢量方向,这也为选频测深法的正演模拟提供了一定的理论参考.When the wavelength of the electromagnetic wave is less than the size of the underground target,electromagnetic waves will be reflected and refracted on the interface of the geological body.However,existing literature does not provide a unified and standardize description of the vector direction of reflection and refraction.Based on this issue,this paper attempts to analyze and explore the propagation laws and directions of reflection and refraction of planar electromagnetic waves at underground conductive interfaces from a theoretical perspective.According to the correlation between electromagnetic wave electric field and magnetic field vector,starting from Snell’s Law,the reflection and refraction problems on the interface of underground good conductors are theoretically derived and analyzed,combined with the practical application of natural electromagnetic method in surface exploration.Through the research,it finds that when the natural electromagnetic signal is incident onto the interface of a good underground conductor,the refracted wave is always in phase with the incident wave;while the reflected signal E_(2)is in phase with the incident signal E_(0)in TE mode,and the reflected signal H_(2)is in phase with the incident signal H_(0)in TM mode.From this,the vector direction of natural electromagnetic signals when reflected at the underground electrical interface can be determined,and this also provides a certain theoretical reference for the interpretation of selective frequency sounding methods.

关 键 词：反射系数 正演 地下水 电磁场 天然电场选频法 

分 类 号：P641.7[天文地球—地质矿产勘探]