Determining changes in building tilts based on UAV photogrammetry

•Methods of determining tilt changes based on orthomosaics and DEM are compared.•Buildings influenced by underground mining are analyzed.•Reference measurements are taken using terrestrial laser scanning.•Orthomosaic-based method achieves slightly better accuracy.•Both methods give a rather general view of the scale of tilt changes. This paper presents the results of a study to determine the accuracy of changes in building tilts based on photogrammetry from unmanned aerial vehicles. The changes in building tilts are calculated from the relative horizontal displacements (HzDiff method) and from the changes in heights of selected points (VDiff). For both methods, the accuracy is analyzed using reference data collected by terrestrial laser scanning. The root mean square error of the estimated total changes in building tilts is 2.7 mm/m for the HzDiff method and 3.3 mm/m for the VDiff method. Both methods provide a rather general view of the scale of tilt changes caused by mining, but do not allow for a detailed analysis of the tilt changes of individual objects.