Comparison between Two Methods for Monitoring Deformation with Laser Scanner

This contribute describes two methods for monitoring and control of mountain areas with Terrestrial Laser Scanner using laser scans performed in two time periods, and having as aim the study of possible deformations. In the first method, the registration of scans at each epoch was made using the algorithm ICP (Iterative Closest Point) while the generation of the DEM for analysis of the ΔDEM differences between the two epochs was made with the RANSAC (RANdom SAmple Consensus) algorithm. With the second method, the registration of the point cloud for each period and then the estimation of displacement took place with a procedure based on the algorithm “Least squares 3D surface matching” without the need to use the target scans and DEM generation