Development and application of a new inversion algorithm for the time domain induced polarisation data in three dimensions

本项目的目标是利用整个时间序列的信息在时域上解释诱导极化。默认情况下，只使用曲线下方的面积或注射期间和注射后的电压进行解释。其目的是开发一种算法，将整个时间序列反演为地下电导率的3D模型。反演是基于Cole-Cole模型或类似的模型，例如Dias（2000）。近似用于在时域中快速直接地计算阶跃响应（Hördt等人（2006），Hönig和Tezkan(2007)）。首先，对不同时间通道的瞬态进行独立反演，得到具有三维直流电阻率代码的地下电导率模型。因此，获得了模型中每个单元的随时间变化的电阻率。然后，可以将随时间变化的电阻率反演为包含用于表征地下特征的附加参数的Cole-Cole模型。使用整个时间序列需要高标准的数据质量和大量的测量工作。在项目的第一阶段，使用Terrameter LS测量的数据满足这些要求，并将使用上述算法进行建模。如果对相同的剖面进行频域和时域测量，也将对它们进行比较。

The goal of this project is to use the information of the entire time series for the interpretation of the induced polarization in time domain. By default, only the area below the curve or the voltage during and directly after injection are used for interpretation.The aim is to develop an algorithm which inverts entire time series into a 3D model of the conductivity of the subsurface. The inversion is based on the Cole-Cole model or comparable models e.g. from Dias (2000).An approximation is used to calculate the step response fast and directly in the time domain (Hördt et al. (2006), Hönig and Tezkan (2007)). First, the transients are inverted independently for separate time channels into a subsurface conductivity model with a 3D DC resistivity code. Thus, a time-dependent resistivity for each cell of the model is obtained. The time-dependent resistivity can then be inverted into a Cole-Cole model which contains additional parameters for the characterization of the subsurface. The use of the entire time series requires a high standard of data quality and a large measuring effort. The data measured with the Terrameter LS during the first phase of the project satisfy these requirements and will be modeled with the above-described algorithm. .If frequency domain and time domain measurements are available for the same profiles, a comparison between them will also be made.