This paper reports on a proof-of-concept test for modeling a dynamic surface by integrating terrestrial laser scanning into videogrammetry. The ultimate objective is to apply the methodology to determine the surface geometry of membrane structures, and retrieve the displacement and deformation information from the sequential three-dimensional model. Due to the characteristics of a membrane surface, conventional targeting is impracticable. Therefore the laser footprints produced during laser scanning, together with projected dots of light, are used as control points and videogrammetric targets, replacing the need for physically attached targets. Following the videogrammetry workflow developed in this experiment, the laser footprints and the projected dots could be extracted from the acquired video imagery and their 3D object coordinates are estimated. Then the surface model is constructed based on the estimated target points.
The originality of this paper is the integration of videogrammetry and terrestrial laser scanning. The introduction of laser scanning not only determines the 3D surface model, but also provides full control in the videogrammetric process. Moreover, the developed system presented herein demonstrates it is capable of constructing the three-dimensional surface model over time.