三维电磁模拟技术及其在频率测深法中应用

利用现有的并矢格林函数和积分方程理论对轴向频率测深三维问题进行正演模拟，并讨论其精度．三维良导体或高阻体的存在对频率测深电场分量Ｅｘ定义的视电阻率响应（振幅、相位）分布特征的影响各有其特殊的规律性．选择测量电极中心作为频率测深三维问题正演计算结果的记录点，既使视电阻率响应在异常体正上方获得最大异常，同时又使正演计算的拟断面图的异常分布与异常体之间有很好的对应关系．

THREE-DIMENSIONAL ELECTROMAGNETIC MODELLING AND ITS APPLICATION IN FREQUENCY-DOMAIN ELECTROMAGNETIC SOUNDING METHODS

The theories of Dyadic Green's function and integral equations are used to carry out direct calculation of three-dimensional problems in frequency-domain electromagnetic sounding methods.The precision of calculation are also discussed.The effect on apparent resistivity curves and pseudo-sections from high-or low-conductivity abnormal bodies each has its own characters.The center of measure electrodes is chosen as the recording point,which makes the apparent resistivity responses acquire maxium abnormaly above the center of the abnormal body,and the pseudo-sections correspond to the abnormal bodles very well. But the suitability of the choice to the field work is to be discussed further.