Automatic Deformation Acquisition using Terrestrial Laser Scanner

Deformation monitoring is typically undertaken using spare, point-wise geodetic surveying techniques, such as total station or GPS. Deformation monitoring using terrestrial laser scanning is gaining considerable attention mainly due to the high spatial resolution of the acquired data. It can provide dense 3D information of the surface of an object. A disadvantage of the technique may be the difficulty to assess some fixed benchmarks on the surface of the deforming area, unless they are special targets that can be recognised by the accompanying software. To solve this problem, a new automatic deformation acquisition method based on nurbs surface was presented. The paper discusses methods of nurbs surface modelling implemented for deformation monitoring and approaches used to measure the deformation from surfaces. Finally, applications involving the use of laser scanning in bridge are presented.