As a highly efficient numerical simulation method, finite element method is widely used in geophysical forward calculation. Whether grid subdivision is suitable or not is the prerequisite for finite element solution. From the aspect of ideal twodimensional medium model, this paper discusses the effect of grid subdivision on magnetotelluric forward modeling precision, under the conditions that the subdivision areas have the same size, the boundary conditions are satisfied, and the sparse and dense mesh are compared. In low frequency phase, two polarization modes were taken as a whole, the coarse grid has higher simulation accuracy than the fine grid, but at the beginning of the near-surface phase under TM mode, the simulation accuracy of the coarse grid is not as high as that of the fine grid. Overall, the coarse grid has more moderate change than the fine grid, and the fluctuation amplitude of the coarse grid and fine grid is higher in the tail of the curve, both of which deviate from the normal value. The results show that proper grid subdivision can effectively improve the accuracy of electromagnetic finite element forward modeling, and it is significant for the subsequent inversion as well.
ZHU Chongli
,
DONG Shuqian
,
ZHOU Diangang
. Influence of Grid Subdivision on the Resistivity Curve[J]. Science & Technology Review, 2014
, 32(11)
: 66
-70
.
DOI: 10.3981/j.issn.1000-7857.2014.11.010
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