地下电波法在深层地下物探中的应用研究

采用矩量法研究了有耗媒质中有限长圆柱对称天线的辐射特性及三维金属地质目标散射特性.首先推导了有耗媒质中圆柱对称天线的海伦积分方程;然后利用等效原理建立导体表面的电流积分方程,并采用伽略金方法将积分方程组转化为矩阵方程组,求解出散射体表面的等效电流分布,计算出其散射场;最后以典型散射体为例,进行了仿真计算分析.数值计算结果表明,采用矩量法所得的数值计算结果与Ansoft HFSS仿真的结果具有良好的一致性,验证了理论分析的正确性与程序编制的可靠性.因此该方法在深层地下物探研究中有一定的理论和应用价值.

Application of EM wave method in deep underground geophysical prospecting

The radiation characteristics of a finite cylindrical symmetry antenna and the scattering characteristics of 3-D geological metal target in lossy material were analyzed by using the moment of method (MoM). Firstly, Hallen integral equation was performed to analyze the antenna. Then, the Equivalent Theory was used to build the electric field integral equation (EFIE), the EFIE was translated into matrix equations by Galerkin method, and the scattering field can be calculated by the surface currents of the metal target. Finally, numerical calculation to representative scatters was conducted. The numerical results were compared to the simulation results by Ansoft HFSS, and it is found that the results have good coherence, which confirms the validity of the theory analysis and the reliability of the program. Hence, this method has some value in deep underground geophysical prospecting.