Temporal and thermal visualization by fusion of thermal images and 3D mesh

Abstract. In the context of the TIR4sTREEt (Thermal InfraRed for Street Trees) project, a huge measurement campaign has been organized. In order to study the interactions between trees and buildings regarding the surface temperature, thermal infrared (TIR) data have been acquired during a long period and from different points of view. Over a period of 17 days, the camera under study has been fixed on a mast and later, for specific days, on a low-cost mobile system. Several thousand images have been acquired. This paper introduces a methodology for creating a temporal thermal 3D model through the fusion of 2D thermal infrared images with 3D mesh models. The purpose of this fusion is to produce an efficient solution for visualization and analysis of detailed spatial and temporal variables like surface temperature. Therefore the temporal thermal 3D model is a faithful representation of reality and serves as a kind of reference model. Subsequently, validation of microclimatic simulation will be achieved by comparing the simulated surface temperature with the thermal reference model. First results show that the fusion is reliable and that this visualization solution is a robust and precious tool for facilitating the validation of microclimate simulation tools.