3D point cloud thermal expansion mapping of heritage building combined with roughness filtering system

Heritage buildings have continuously experienced repeated thermal expansion and contraction due to climate change and environmental changes like seasonal effects. Especially in recent years, due to extreme climate change, heritage buildings are experiencing climates they have never experienced before and it can affect movement such as tilting in heritage buildings. In this paper, we presented a 3D point cloud thermal expansion mapping combined with a roughness filtering system to measure the thermal expansion and contraction of heritage buildings that can occur in winter. The roughness filtering system calculates the threshold for filtering through the intersect method in the roughness histogram. Therefore, rough or curved areas such as decorations that cause errors when calculating thermal expansion in heritage buildings can be removed. This filtering system not only reduces errors in thermal expansion mapping, but also drastically reduces thermal expansion evaluation time. In this paper, the proposed system was applied to the Victoria Gallery and Museum (VG&M), and the winter thermal expansion and contraction phenomena were identified. Satellite data was analysed to find out the correlation between environmental factors and thermal expansion, and it was confirmed that solar radiation affects thermal expansion.