High-resolution 3-D dielectric property models of the shallow subsurface: Integrating direct-push and georadar data

在过去的几十年里，地质雷达数据分析已经成为探测浅层地下的关键地球物理技术之一。在典型的地质、环境和工程应用中，该技术提供了详细的地下2-D/3-D图像。然而，对产生的反射图像的分析通常限于构造解释，例如，勾勒地质或岩性边界。由于通常无法获得关于地下速度变化的准确和可靠的信息，生成可靠的深度模型仍然是一个具有挑战性的问题。此外，对于分别提供岩石物理参数和岩性估计的更定量解释的实用方法的开发在很大程度上尚未开发。在这个研究项目中，我们希望开发先进的分析方案，以提高地质雷达反射数据的深度定向定量解释。规划开发的核心是将直推式参数信息整合到地质雷达处理和解释流程中。使用特殊的直推式工具可以提取被探测材料的电学和介电性质的高分辨率垂直剖面。由于这些参数指导着地质雷达波的传播，因此在单个位置采集的直推数据可以用来标定2-D/3-D地质雷达反射特征。由此得到的2-D/3-D深度校准的介电参数信息还将提供与许多现场特征研究中所需的进一步重要的岩石物理参数(例如，水含量或孔隙度)的联系。

Within the past decades, georadar data analysis has been established as one of the key geophysical technologies for exploring the shallow subsurface. In typical geological, environmental, and engineering applications, the technique provides detailed 2-D/3-D images of the subsurface. However, the analysis of the resulting reflection images is usually limited to a structural interpretation, e.g., outlining geological or lithological boundaries. As accurate and reliable information on subsurface velocity variations is usually not available, the generation of reliable depth models is a remaining challenging problem. In addition, the development of practical approaches for a more quantitative interpretation providing estimates on petrophysical parameters and lithologies, respectively, is largely untapped. In this research project, we want to develop advanced analysis schemes to improve the depth oriented quantitative interpretation of georadar reflection data. The core of the planned development is the integration of direct-push parameter information into the georadar processing and interpretation flow. Using a special direct-push tool allows for extracting high-resolution vertical profiles of the electrical and dielectrical properties of the probed material. As these parameters guide georadar wave propagation, the direct-push data collected at single locations can be used to calibrate the 2-D/3-D georadar reflection signature. The resulting 2-D/3-D depth calibrated dielectric parameter information would also provide a link to further important petrophysical parameters (e.g., water content or porosity) needed in many site characterization studies.