Abstract：Most instruments of transient electromagnetic method (TEM) can survey three-component field at the same time; nevertheless, the current interpretation technique is only based on the vertical component. In order to use the information of three-components, the authors introduced a constrained inversion method with the three-component field data. The basic idea is to get the full-zone apparent resistivity from the three components of TEM and, on such a basis, to establish the initial model and use the conjugate gradient method to realize three-component inversion. The first step is to take the loop as the superposition of many electric dipoles so as to get the three-component responses of the loop on the basis of electric dipole superposition. Besides, the definition of the full region and all time apparent resistivity can be deduced. After that, the smoking ring theory is adopted to get the apparent depth, which is finally taken as the initial model in inversion. Lastly, the conjugate gradient method is used to realize three-component constrained inversion. Some models were used to test the apparent resistivity definition, and the results show that the apparent resistivity curves match well with the given models. Then based on the apparent resistivity results, the authors established an initial model and used three-component constrained inversion to conduct the inversion of layered models. The final results match well with the given models.
戚志鹏, 智庆全, 李貅, 曾友强, 张莹莹. 大定源瞬变电磁三分量全域视电阻率定义与三分量联合反演[J]. 物探与化探, 2014, 38(4): 742-749.
QI Zhi-Peng, ZHI Qing-Quan, LI Xiu, ZENG You-Qiang, ZHANG Ying-Ying. The definition of the full-zone apparent resistivity and the constrained inversion of the three components of fixed source TEM. Geophysical and Geochemical Exploration, 2014, 38(4): 742-749.
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