The spatial coordinates projection method for generating digital geologic cross sections from the multi-source terrain and geologic data

The geologic cross-section is an indispensable complement to the geologic map and is the model that represents the underground extension of the materials of the structures. It still lacks an automatic way to adapt to digital transformation. A novel method is proposed to improve the efficiency and accuracy of geologic cross-section construction by spatial data projection. The method has three main steps as follows: 1) Calculation. All key components on the cross-section, including topographic profile and structural data, are automatically generated through a relational database table. 2) Spatial coordinates projection. A cross-section in a free direction comes from the projection of a three dimensional data source. The geometric parameters of the geologic cross-section are obtained through the dimensionality reduction projection of the point coordinates. 3) Data extension. The extension of geologic structures in the subsurface and denuded areas and the spatial relationship between contact lines and topographic profiles are discussed. Four case studies, including Digital Contour Map, Remote Sensing, Global Navigator Satellite System (GNSS), and Laser rangefinder, successfully demonstrate that the proposed method is a simple, flexible, fast, precise, and visual process that can generate digital cross-sections automatically and efficiently through multi-source topographic and geologic data.