Development of panoramic infrared images for surface temperature analysis of buildings and infrastructures

Abstract

The surface temperature distribution of buildings and infrastructures is a key piece of information in the analysis of built environments especially in urban areas. It not only helps understand and model the thermal performance of buildings, but also reveal the thermal environments exposed by pedestrians. The information may further help improve the energy efficiency of buildings and reduce the urban heat island (UHI) effect. However, effective methods are currently lacking to visualize and analyze the overall surface temperature of buildings and urban infrastructures in a large scale. To cover this gap, a systematic approach is developed in this study to generate panoramic infrared images. The approach includes: (1) use of a ground-based imaging system to capture visual and infrared images, (2) development of spatial transformation models between the visual and infrared images using intensity-based image registration method, (3) creation of the panoramic visual image and fusion of the panoramic visual and infrared images, (4) geometrical transformation of the panoramic images with a modified cylindrical projection method. Three cases are used to illustrate the potential applications of the approach in the analysis of building surfaces. The cases indicate that the methods can effectively reveal the temporal and spatial temperature variations of large building surfaces, providing insights on the effects of cladding materials on surface temperature.