【摘要】 通过对浅地表电磁探测系统的探测原理和收发天线的结构及参数研究,分析了频率域浅地表探测系统的工作原理。论证了利用磁场z分量间接探测浅地表地下介质电性结构的可行性。利用MATLAB对发射接收天线进行理论计算,分析了收发天线设计的关键问题;重新设计了探测系统所需的发射和接收天线,采用并联结构使发射天线效率有所提高,接收天线采用8字形结构,从结构上实现一次场的屏蔽,同时,避免了引入参考线圈使结构和计算复杂。通过实际测试,能够辨别出埋藏于土壤9 cm处的2 g电阻率异常体。最后,总结了埋藏深度、有无土壤对探测数据的影响。为浅地表探测天线系统的改进及近地表电磁成像系统研制提供依据及参考。更多还原

【Abstract】 The working principle of the shallow surface detection systems in the frequency domain is analyzed by studying the shallow surface electromagnetic detection system as well as the structure and parameter of the transmitting and receiving antenna. The feasibility demonstration to detect electrical structure of shallow surface underground media using the z component of the magnetic field indirectly is carried out. The theoretical calculation is conducted on transmitting and receiving antenna using MATLAB,and the key technologies for antenna design are discussed. The transmitting and receiving antennas of detecting system is redesigned. As a result,the transmitting antenna efficiency is improved with parallel structure,and the receiving antenna uses 8-shaped structure to shield the primary field. In addition,the increasing of complexity of the structure and calculation can be avoided with reference coil. The actual experiments are implemented to indicate that the designed antenna is capable to identify 2g resistivity anomalies buried under the depth of 9cm. Finally,the influence of buried depth and existent soil on detection data is summarized. This work can provide a basis and reference for the improvements of shallow surface detection antenna system and the developments of the near-surface electromagnetic imaging system.更多还原