有限长接地导线源电磁场三维正演研究

Study on 3D Forward Modeling of Finite-length Wire Source electromagnetic field

长接地导线源的一维解析解可以通过对电偶极源解沿导线方向积分获得,而三维模型中则难以直接加载。这里将长接地导线源看作多个电偶极源的组合,利用交错采样有限差分法,进行了直接计算电场总场的有限长接地导线源电磁场三维正演研究,并验证了算法的正确性。正演模拟时为消除场源奇异性,用电流密度呈伪delta函数分布的等效源来代替点源。

The one-dimensional analytical solution of the long grounded wire source can be obtained by integrating the electric dipole source solution along the wire direction.However,loading it directly into the three-dimensional model isn't easy.In this paper,the long grounding wire source is regarded as a combination of multiple electric dipole sources,and the 3D forward modeling of the electromagnetic field of the finite-length grounding wire source directly calculating the total electric field is carried out by using the interleaved sampling finite difference method.The correctness of the algorithm is verified.In order to eliminate the singularity of the field source during forward modeling,the point source is replaced by an equivalent source whose current density is distributed as a pseudo-delta function.