School of Electronic and Information Engineering,Beijing Jiaotong University,Beijing　 100044,China

分层地层对透地通信电磁波的传播特性有重要影响。现有的研究主要是基于规则分层地层模型对电磁波透地传播特性进行分析,但分层地层往往是不规则的。为此,基于所建立的不规则分层地层模型,将分层地层模型分界面抽象为平面、正斜面和负斜面。根据电磁波入射角与分层地层倾斜角的几何关系,推导了电磁波在不规则分层地层中正向和反向传播时电场强度和磁场强度的衰减情况。仿真表明分层地层的不规则性与电磁波进入分层地层介质的先后次序均对电磁波的传输衰减有重要影响。虽然电场强度和磁场强度随着透地距离的增加都显著地衰减,但电场强度和磁场强度的衰减特性并不相同。此外,无论是对电场还是磁场,由于在分层地层分界面电磁波都要产生反射,因此,电磁波在进入到另外一层媒质时电场强度和磁场强度都会产生一定程度的突变衰减。

Layered strata have an important influence on the propagation characteristics of electromagnetic wave through the earth communication. The existing research is mainly based on the model of regular layered strata to ana- lyze the propagation characteristics of electromagnetic wave through the earth. However,the layered strata tends to be irregular. Therefore,the interface of layered strata is abstracted into plane,positive and negative slope based on the model of layered strata established. According to the geometrical relationship between the incident angle of electromag- netic wave and the inclined angle of layered stratum,the forward and reverse transmission attenuation characteristics of electromagnetic wave through irregular layered strata both for electric field intensity and magnetic field intensity are derived. Simulation results show that both the irregular of layered strata and the order of electromagnetic wave entering layered strata have an important influence on the transmission attenuation of electromagnetic waves. Although electric field intensity and magnetic field intensity are attenuated severely with the distance increase though the earth,the at- tenuation characteristics of electric field intensity and the magnetic field intensity are not the same. In addition,due to the reflection of electromagnetic wave in the interface of layered strata,electric field intensity and magnetic field inten- sity will attenuate abruptly to certain extent when entering into another layer.

国家重点研发计划重点专项资助项目(2016YFC0801800)；国家自然科学基金资助项目(51474015,51274018)；

Tang Tongtong,Yang Wei,Shao Xiaotao. Transmission attenuation characteristics of electromagnetic wave through irregular layered strata [J]. Journal of China Coal Society,2017,42(7):1912-1918.