Using UAV photogrammetry to document rock outcrops.

The purpose of this article is to present the usability of UAVs for the creation of large-scale photogrammetric documentation of geological rock outcrops, including their inaccessible parts. Currently manufactured low-cost UAV carriers are an interesting and progressive solution in terms of the processing cost for documentation of geological phenomena. Their main shortcomings are compact digital cameras used due their low weight with respect to the capacity of these UAVs. In our research, we aimed to verify the usability of digital photogrammetry with UAV for geological documentation of rock outcrop. This issue is addressed in several papers (Fritz et al., 2013; Niranjan et al., 2007) and produces interesting results. Our aim was to test a mass-produced, low-cost UAV model to create photogrammetric documentation of the surface quarry Lehôtka pod Brehmi. In this quarry, there is a large artificial rock outcrop, which was formed by mining activities. This outcrop is interesting in terms of the amount of information about the geological structure of the deposit, which can be observed in one place. A large part of the outcrop is inaccessible due to the total height of the outcrop, which is about 75 m. The entire outcrop has been photogrammetrically imaged using UAV. The integrated photo profile was created in the software environment Agisoft PhotoScan. For the purpose of visualization, a 3D model of the whole outcrop was also created. Obtained data will then serve as a basis for the model of the geological structure of deposits. [ABSTRACT FROM AUTHOR]