WORKFLOW BETWEEN TERRESTRIAL LASER SCAN AND UAV PHOTOGRAMMETRY FOR STRUCTURAL ANALYSIS OF BRIDGES

The structural analysis of the civil infrastructure is vital in order to track the evolution of degradation in time, to prevent disasters, but also to document and conserve the sites of cultural heritage. This paper review�s the workflow on the acquisition of point clouds to Terrestrial Laser Scanner (TLS) with those collected by photogrammetric 3D models based on images captured by an unmanned aerial vehicle (UAV), analyzing the data sets on two diferent type of bridges located in western Romania. The obtained data can serve a wide range of applications and supports different studies, also providing new digital tools that help tracking the degradation in time, reducing the technical limitations in the cultural heritage preservation, and exploring alternative ways for shaping future steps associated with saftey inspection. Depending on the objective, the use of such integrated technologies brings a significant contribution as a support tool for decision making. Due to the geometric complexity of the structure, the accuracy of measurements was limited by the resolution of sensors (remote-sensing data) and areas without light, hard to reach by lens. The comparative analysis of the two techniques shows that both methods produced similar results with high precision but also presented disadvantages in terms of data associated with spatial features.