Combined use of Terrestrial Laser Scanning and UAV Photogrammetry in producing the LoD3 of 3D high building model

Both Unmanned Aerial Vehicles (UAVs) and Terrestrial Laser Scanners (TLS) are important techniques for surveying and mapping. UAV equipment is commonly used to collect 2D or 3D data acquisition. Meanwhile, TLS equipment is used for obtaining only 3D data acquisition. However, if both are integrated, they were able to produce more accurate data. Multi-sensor data fusion helps overcome the limitations of a single sensor and enables a complete 3D model for the structure and better object classification. This study focuses on studying the combination of UAV and TLS technologies to collect, process data, and create the complete point cloud between two point clouds of the high building in Ha Long city, Quang Ninh province to establish a 3D model at LoD 3 detail level, with high accuracy. FARO FOCUS3D X130 and DJI Phantom 4 RTK equipments were used to acquire the data in the field. The aerial and ground data were processed using FARO SCENE 2019 and Agisoft PhotoScan software, respectively. The data integration process is done by converting both point clouds into the same coordinate system and then by aligning the same points of both points clouds in Cloud Compare. The result of this study is a 3D model at LoD 3 detail level of the high building based on the point cloud accuracy in centimeter level. The combined use of UAV and TLS technologies has proven to be possible to create a highly accurate 3D model, at the 1:500 scale of urban areas according to current standards.