Imaging and photogrammetry models of Olduvai Gorge (Tanzania) by Unmanned Aerial Vehicles: A high-resolution digital database for research and conservation of Early Stone Age sites

This paper presents the first aerial mapping of Olduvai Gorge (Tanzania) using Unmanned Aerial Vehicles and photogrammetric techniques, to provide a detailed digital cartographic basis for this world-renowned paleoanthropological site. The survey covered an area of 32 km2 of Olduvai Gorge, and through the use of aerial photos and ground control points from Global Navigation Satellite Systems, an orthomosaic and Digital Surface Model, with a higher than 5 cm/pixel ground resolution, were produced. The Digital Surface Model was then denoised to calculate a Digital Elevation Model, and a high-resolution imaging model of Olduvai Gorge was generated. A preliminary morphometric characterization using Geographic Information Systems shows the potential of this approach when analysing multiple topographic variables in large areas of paleoanthropological relevance, including production of a new map template for Olduvai Gorge and new data for the investigation of sedimentary and tectonic processes. These results constitute one of the first attempts to obtain high quality imagery from large geographic areas amenable to Early Stone Age research, and introduce new workflows for the creation of Digital Elevation Models. Overall, the digital dataset produced is intended to support archaeological and geological investigation in this area, and provide new monitoring tools for the conservation of cultural heritage.