Electromagnetic (EM) sounding methods in the time and frequency domains are widely used in polymetallic ore exploration and can measure both EM induction and induced polarization (IP) responses simultaneously. Depth inversion is a crucial factor affecting the accuracy of data interpretation. The effect of IP on EM wave propagation has been ignored in traditional studies of diffusion depth and skin depth. This article is based on the generalized effective-medium theory of the IP effect (GEMTIP) model to represent the IP effect. The frequency domain solution based on GEMTIP is obtained. To address the problem whereby the time-domain solution cannot be solved by inverse Laplace transform, rational approximation and linear programming methods are used to simulate the variation of pulse field source with time and distance. We analyze the influences of geometrical parameters and physical properties of rocks and ores with the IP effect on the depth. Finally, we consider the influence of intrinsic chargeability and improve the classic diffusion depth formula. The formulae for estimating the time-domain diffusion depth of the IP effect under certain conditions are given and verified. These methods are of great significance to better understand the relationship between the subsurface dispersive media and the propagation of EM waves.

中文翻译：

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电磁测深方法中基于GEMTIP模型的扩散深度和趋肤深度的数值计算


时域和频域电磁 (EM) 探测方法广泛应用于多金属矿勘探，可以同时测量电磁感应和诱发极化 (IP) 响应。深度反演是影响数据解释精度的关键因素。传统的扩散深度和趋肤深度研究中忽略了IP对电磁波传播的影响。本文基于IP效应的广义有效媒介理论（GEMTIP）模型来表征IP效应。得到了基于GEMTIP的频域解。针对拉普拉斯逆变换无法求解时域解的问题，采用有理逼近和线性规划方法模拟脉冲场源随时间和距离的变化。我们分析了岩石和矿石的几何参数和物理性质与IP效应对深度的影响。最后，我们考虑了本征荷电率的影响并改进了经典的扩散深度公式。给出并验证了一定条件下IP效应时域扩散深度的估计公式。这些方法对于更好地理解地下色散介质与电磁波传播之间的关系具有重要意义。