Integrating UAV Photogrammetry and Terrestrial Laser Scanning for the 3D surveying of the Fortress of Bashtova

Through the synergistic application of Aerial Photogrammetry using UAVs and Terrestrial Laser Scanning (TLS), this paper investigates how this combination can be used for conducting a 3D survey of the Fortress of Bashtova thereby demonstrating the effectiveness of such integrated methods in acquiring an all-encompassing image of this historical building. As the efforts towards preservation become intense, there arises the urgency of precise and detailed 3D documentation that will facilitate appropriate conservation processes and further studies. Therefore, combining TLS and UAV photogrammetry offers a powerful tool that can provide accurate architectural data for the documentation of heritage areas. Moreover, the TLS component acquires ground point-cloud data with laser scanners giving a complementary alternative for aerial perspective. The merging of these datasets ensures broad inclusion since it allows the production of accurate, detailed three-dimensional models of the Fortress of Bashtova. Thanks to the research on the case study of the Fortress of Bashtova in the article, it can be stated that the integration of data from aerial photogrammetry and TLS is seamless with the help of modern software while respecting the basic photogrammetric-geodetic rules and demonstrates the possibility of creating a complex 3D model, usable for further analyses for architects and conservation professionals, as well as for restorers and civil engineers. To estimate the accuracy of the point clouds derived from TLS and UAV, we compared the distances between the point clouds using CloudCompare software. We obtained a mean RMS of 2.199073 mm and std. dev was 7.356 mm. Research has shown that the difference between point clouds from TLS and UAV is within 1.7 centimeters.