Thermal and spatial data integration for recreating rebuilding stages of wooden and masonry buildings

Abstract

This paper describes the means of supporting virtual reconstruction of wooden and masonry buildings with the use of thermal infrared images. Not all remaining architectural heritage can be physically preserved. War, climate change and rapidly growing cities have caused damage and degradation to valuable historical buildings. In order to preserve them virtually, various methods of 3D modelling have been employed. This paper presents information on how to create a full 3D inventory of a building’s exterior. This includes a 3D thermal model of the building, merging thermal camera data with a spatial model, which aids the reconstruction of previous stages of a building’s existence. The authors argue that in cases when it is impossible to force heat transfer from inside the structure (via man‐made heating), 24 hours of observations using only solar heating can be sufficient to find heat bridges and other thermal anomalies that can be used for virtual reconstruction.

Use of 3D Inferred Imagining for Detection of Changes in Geology in Longwall-Type Excavation Front

“…This could be mitigated by using a TLS unit with an IR camera, such as the Z + F 5100c with an IR camera mount, but this operation would still take a lot of time and require a relatively long stop of excavation. Moreover, based on the author's experience, the survey's time makes integrating scans performed in changeable conditions difficult, making it imperfect for accurate change detection [17,24].…”

“…Depending on the object's surface characteristics and the composition below the surface, the energy also in the form of the heat reaching an object can be absorbed, reflected, or transmitted. This means that the value to be calculated is usually performed accurately only in a controlled setting, where no additional energy sources exist [3,24]. A radiation analysis is conducted in three areas of the infrared spectrum NIR (near infrared) 0.78-3 µm; MIR (mid-infrared) 3-50 µm; and FIR (far-infrared) 50-1000 µm.…”

“…Thus, defining the value of monochromatic emissivity in field conditions is difficult, so the post-processing procedure is required. In addition, Equation (3) introduces both vertical and horizontal viewing angles, so distortions in both directions are different [24,25,41,42]. Experiments also suggest that not only the general environment needs to be taken into account but also the distance to the object and the placement of the IR camera relative to the object [43].…”

“…The camera used was a ThermaCAM™ P60 (temperature range −40 to +2000 • C in various settings; thermal sensitivity 0.8 • C; accuracy ±2 • C ±2% of reading, focal plane array (FPA) detector, uncooled microbolometer; 320 × 240 pixels. This is a relatively small pixel-size camera with a high-quality sensor, so it can be used to detect even the smallest changes in temperature [24]. The first step of processing involved creating a combined image of the excavation front.…”

“…This means that if the air between the camera and the object has a significant shift in temperature (such as a draft of fresh air), this will obscure the reading. The camera needs to be properly calibrated for such an environment, which may not always be possible [24,25]. All of those limitations, aided by safety regulations in the mining industry around the world, have made the use of IR cameras less common than they have the potential to be.…”