Laser scanning intensity fingerprint: 3D visualisation and analysis of building surface deficiencies

Abstract

Terrestrial laser scanning (TLS) is a widely used technology in numerous sectors since it enables the recording of both geometric data and colour information of the objects. Moreover, this remote sensing technique allows for producing point clouds enhanced with the reflection intensity of the laser beam. Scientific research has used those data to detect and assess building surface deficiencies. However, the laser scanning intensity fingerprint of a building pathology is yet to be addressed. Thus, this research quantitatively analyses the distribution of point cloud intensities throughout the object geometry to show changes against the general context of the building component surface. This intensity fingerprint reveals the extent of the pathology, which leads to filtering the point cloud by those intensity values to extract and calculate the surface defect. On this basis, TLS is proven to be useful to record, detect, characterise, and examine specific building surface deficiencies and carry out the conservation status analysis of the assets surveyed. The case studies in this chapter are heritage buildings with clear surface pathologies. However, given the relationship between the building surface deficiencies and the point cloud data intensities, this research can also be applied to detect anomalies in modern buildings and constructions.