Documentation of complex structure using unmanned aerial vehicle (UAV) photogrammetry method and terrestrial laser scanner (TLS)

Abstract

Modeling objects with different sizes and geometries and analyzing metric information is more difficult than regular geometric structures. The analysis and measurements of conical, spherical, and cylindrical structures such as minarets, domes, columns, statues, and monumental tombs cannot be accurate and precise with classical methods. Three-dimensional (3D) scanning technologies such as Terrestrial laser scanner (TLS) are an important tool for modeling complex structures. Undoubtedly, 3D scanners are well suited for measuring objects with irregular and complex surfaces and are probably one of the best methods for applications with similar structures. However, the biggest disadvantage of ground base scans such as TLS is that the data of the upper facades of the structure cannot be collected due to the scanning location. This problem can be overcome by collecting data on the upper fronts of the structure by platforms such as unmanned aerial vehicles (UAV). Therefore, in our study, the data were collected by TLS and UAV photogrammetry methods, and then the 3D model and analysis of the complex structures were made by combining the obtained data. As a result of the study, 0.21-2.3 cm accuracy was calculated for point clouds produced by TLS and UAV photogrammetry, respectively. By combining the point clouds created from both data collection methods, 1.2 cm sensitivity was calculated.