Use of 3D models obtained with photogrammetric methods in an industrial mineral mine
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3D models in underground mine could become an alternative or addition for mine surveying works. Furthermore, the data could be collected by less specialized mine workers, while generated photogrammetric products support other disciplines in the mining sector.The primary subject of this thesis was to establish a method which could enable a monitoring progress of exploitation works in terms of mapping drifts using 3D models. The method provides essential information about the direction in which drifts are excavated and enable to control the minimum distance between neighboring drifts before the next surveying measurements are conducted. First steps for establishing the method took place in a testing tunnel at NTNU and they consisted of setting up photo acquisition pattern and georeferencing 3D models. Among two cameras which were tested, GoPro camera was chosen as the most adequate to apply during a research in the mine. Moreover, there were two application Context Capture and Agisoft PhotoScan employed to produce 3D models. By comparison of the results between two programs, it was decided to use Context Capture for processing data captured in the mine. The test in NTNU tunnel showed some imperfections in data acquisition patter, thus some improvements were implemented. The research conducted in the mine proved that the method works in real conditions. Models presenting the situation in drifts were produced. Pictures taken before every blast allow us to prolong model and show the progress of exploitation works. However, due to many faces in production during the research period the accuracy of mapping was assessed only on a base of data captured for 3 blasts, which was close to the accuracy provided by total station measurements. For that reason, it was decided to conduct additional tests in an already excavated drift to obtain an accuracy indicator of mapping with 3D models concerning the longer part of a drift. The long model of the excavated drift was generated and the results brought surprisingly good accuracy for mapping 150 meters long drift. This master thesis also provides proposals of other applications of 3D models in underground mine connected to the mining operations. Especially, topics concerning geology such as structural analysis, geological interpretations, surveillance and documenting rock mechanics problems.