Accurate and Cost-Efficient 3D Modelling Using Motorized Hexacopter, Helium Balloons and Photo Modelling: A Case Study

The destructive nature of archaeological excavations and the spatial character of archaeological finds make 3D models valuable contributions to the documentation of archaeological information. Laser scanning allows highly accurate 3D reconstructions, but involves considerable costs and expert knowledge. Therefore, photo modelling could be considered as a useful alternative. In this paper, we will demonstrate on the one hand the cost-efficiency and the consequent time-efficiency of the technique and on the other hand its (sub-decimeter) accuracy. Furthermore, the possibilities and advantages of motorized unmanned aerial vehicles (UAV) and helium balloons as airborne platform for image acquisition are shown. For this purpose, a case study is performed at the Mayan archaeological site of Edzna (Mexico). Using the Structure from Motion (SfM) and Multi-View Stereo (MVS) algorithm, terrestrial and aerial photographic recordings are processed into the final 3D models. For the quality assessment the photographic recordings are supplemented with topographic measurements.