Integrated application of LiDAR and photogrammetry in geological logging

摘要

Geological Logging plays a vital part in hydropower and traffic engineering construction. In view of the current problems existing in engineering geological logging, this paper proposes a new engineering geological logging approach, which integrates LiDAR techniques with digital close-range photogrammetry. In this approach, firstly, acquire digital images and point cloud of engineering excavation surface by high-resolution digital camera and three-dimensional laser scanner respectively. Secondly, project point data onto a raster image, after which, mark points will be extracted from point cloud raster image and digital images with the help of image processing technology. Lastly, calculate the exterior orientation elements of digital images by the close-range photogrammetric space resection algorithm, and then register point cloud with digital images by collinearity equation. As a result, two computer-aided logging methods are also presented: one is two-dimensional image logging method based on the single image projection transfer algorithm, the other is logging in three-dimensional virtual environment after three-dimensional reconstruction of engineering excavation surface. The practical applications have demonstrated that the approach proposed in this paper has a great improvement in efficiency and precision of geological logging.