Ondrej TRHAN, Marek FRAŠTIA, Marián MARČIŠ

Tvorba priestorových modelov budov z dát získaných pomocou fotogrametrie UAV

Trhan, O., Fraštia, M., Marčiš, M.: The creation of spatial models of building using UAV photogrammetry data. Kartografické listy, 2016, 24 (1).

Abstract: The main part of the spatial city models are buildings. These buildings can be created using various ways. Most works use data obtained from the LiDAR systems or from the stereoscopic models from airborne photogrammetry. In our case we use the automatically obtained data from UAV (Unmanned Aerial Vehicle) photogrammetry. Nowadays, this photogrammetric method is widely spread, because of the speed of the data obtaining, financial demands and high precision. We use the digital surface model in the form of the pointcloud and the true orthophoto as the input data. The reason, that the building walls are not perpendicular is the main problem of the automatic pointcloud processing and this leads to some errors in the true orthophoto. In our work, we edit the photogrammetric data in some steps. In the first step, we arrange the digital surface model to the grid, which has the same size as the true orthophoto. The second step is a creation of the digital terrain model. The digital terrain model is created using the progressive morphological filter and it is used for the creation of the basic digital mask. This digital mask is used for the detection of the building outlines. In the next step is this digital mask modified and applied to the orthophoto. In the masked areas are the building edges detected, which can be considered as the building outlines. These outlines are the base to the creation of the building areas. In these areas, we can generate the spatial building model in the level of detail 1. After these steps, we obtained the digital terrain model with buildings on it, which are geometrically and positionally correct and the walls of the buildings are perpendicular.

Keywords: photogrammetry, DSM, DTM, orthophoto, spatial building model, UAV