Comparative Study of Two Approaches for Application of Terrestrial Laser Scanner in Structural Health Monitoring and Damage Assessment

Abstract

The main objective of the paper was to evaluate two approaches aimed at tracking small displacements. The first approach is based on the usage of laser targets commonly used for stitching point clouds together. The second approach is based on the estimation of a corner of a prismatic shape and utilizes thin horizontal slices of the shape’s point cloud. The corner’s location is estimated as an intersection of two straight lines best fitted to the point clouds before and after the corner. It was shown that for both approaches a sub-millimetre accuracy can be achieved. The first approach requires the installation of two laser targets in order to measure the change of the distance between them. The second approach offers more flexibility because it does not require the installation of a laser target. Hence it can be used in the quantitative assessment of structural damage in the aftermath of natural disasters such as earthquakes, fires, tsunamis, landslides and hurricanes,