中文摘要：

为解决模拟瞬变电磁场在3维介质中传播出现的计算量大、对计算机要求高等问题，使用了3维磁偶极源来模拟2维均匀介质和层状介质中方形和薄板低阻体的全空间响应特征。模拟中使用了时域有限差分法，采用非均匀网格和时间步长，分析了瞬变电磁场在均匀介质和层状介质中的传播规律，以及巷道和交界面对场的影响特征，为解释全空间均匀介质和层状介质TEM异常提供参考。

英文摘要：

Because of the huge computation and limitation of computer resource when modeling the diffuse of the transient field in three dimensional medium, FDTD, the nonuniform grid and time step length will be used to study the whole-space response characteristic of two dimensional square and sheet conductive body, located both in uniform medium, and in the layered medium, with a 3 dimensional magnetic dipole, And the diffused regularity of the transient field in them, the effect of laneway and boundary will be also discussed, The objectives are to provide interpretation guidelines for the TEM anomalies arising from the full-space uniform and layered medium.