Tls Deformation Measurement Using Ls3d Surface and Curve Matching

During last few years the use of Terrestrial Laser Scanner has increased notably in different application fields, like architecture, geology and geodesy. The paper focuses in the use of TLS data for deformation measurement and monitoring purposes which concerns both engineering geology and geodesy. The paper presents a new approach for deformation measurement which fully takes advantage of the TLS data characteristics. The procedure is based on the point cloud matching algorithm Least Square 3D Surface Matching proposed by Gruen and Akca (ISPRS Journal, 2005, 59, 151-174). The proposed approach takes advantage of both surface and curve matching to improve the co-registration quality and it exploits the high density of TLS point clouds, which counterbalances the relatively poor precision of the single TLS points. The work describes the proposed deformation measurement procedure, and discusses in particular some results of the research made at the Institute of Geomatics: the preliminary results obtained with curve matching.