The time-domain electrical source electromagnetic detection method is an effective and fast method for detecting mineral resources.The polarization effect can lead to rapid attenuation of the electromagnetic response and even a symbol reversal phenomenon.In this paper,the Cole-Cole model is used to describe the polarization effect,and arbitrary fractional Cole-Cole models are rationalized by using the integer order rational approximation algorithm.Yee's grid is used to divide the simulation area,and the three-dimensional numerical simulation of induction-polarization effect of electrical sources is realized based on the finite difference time domain(FDTD)method.The electromagnetic responses of three typical models,namely uniform half-space model,polarized half-space model and three-dimensional polarized body model,are numerically simulated.The results show that the electromagnetic response of uniform half-space model is basically consistent with the analytical solution,and the relative error is less than 10％,which proves the feasibility of the three-dimensional numerical simulation method.The electromagnetic responses of polarized half-space model and three-dimensional polarized body model both have negative responses in the late stage,which is consistent with the polarization theoretical results.
维普
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