Approximate calculations of the transient electromagnetic response from buried conductors in a conductive half-space
Approximate calculations of the transient electromagnetic response from buried conductors in a conductive half-space
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DOI：
10.1190/1.1441737
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发表时间：
1984-07
期刊：
影响因子：
3.3
通讯作者：
J. D. Mcneill;R. N. Edwards;G. M. Levy
中科院分区：
文献类型：
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作者：
J. D. Mcneill;R. N. Edwards;G. M. Levy
以启发式方式研究了埋在导电半空间中并由大回路发射机激励的导电板的瞬变电磁（TEM）响应。涡流和电流分量分别直接在时域中使用近似程序计算，该近似程序忽略了完整解中存在的电磁耦合。在对涡流和电电流流动进行建模时，该板分别被具有适当参数的单圈导线回路和电流偶极分布所取代。文中给出了几种有实际意义的情况下地球表面瞬态磁场的计算结果。涡流和电流分量的相对重要性随半空间电阻率而变化。如果半空间是电阻性的，则涡流分量占主导地位，在这种情况下，自由空间算法足以进行数值建模。此外，测量的响应提供了许多有用的信息的目标，…
The transient electromagnetic (TEM) response from a conductive plate buried in a conductive half‐space and energized by a large‐loop transmitter is investigated in a heuristic manner. The vortex and galvanic components are each calculated directly in the time domain using an approximate procedure which ignores the electromagnetic coupling present in the complete solution. In modeling the vortex and galvanic current flows, the plate is replaced with a single‐turn wire loop of appropriate parameters and a distribution of current dipoles, respectively. The results of calculations of the transient magnetic field at the surface of the earth are presented for a few selected cases of practical interest. The relative importance of the vortex and galvanic components varies with the half‐space resistivity. The vortex component dominates if the half‐space is resistive, in which case free‐space algorithms suffice for numerical modeling. Furthermore the measured responses give much useful information about the target,...