ACCURACY ASSESSMENT OF BUILDING MODELS CREATED FROM LASER SCANNING DATA

Abstract

Recently, it can be observed a growing interest in 3D building or city models created from laser scanning data. These models are used in many areas of interest. In this work the accuracy assessment of 3D buildings models created from airborne and terrestrial laser scanning data was carried out. TLS data for modelling were acquired with average point spacing about 0.02 m. In order to model invisible from the ground building elements such as roofs, the LIDAR data was used with density of about 12 pts./m2. TLS and LIDAR data were acquired in the same coordinates system. For textures mapping a set of 10 Mpix digital images using SLR camera Canon 40D were taken. Modelling was performed using both commercial software Leica Cyclone, as well as original software and free software. The accuracy of models is affected by many factors, but the impact of all factors leading to errors of the final models were analysed together. The accuracy of models was assessed by comparing the coordinates of characteristic points of the models and the corresponding coordinates of these points measured on real buildings. The accuracy of points measured on the real building was not affected by model errors, therefore they can be treated as error-free reference points. On site reference measurements were performed using Leica TCR407Power reflectorless total station. Obtained inaccuracies of the reconstructed models were as follow: 0.12 m horizontal, 0.1 3m vertical, 0.18 m three-dimensional.