ABSTRACT
Breakwater monitoring is essential to determine their condition state and decide necessary maintenance operations. This manuscript presents three different techniques for monitoring the emerged area of breakwaters. The techniques are based on static photogrammetry, aerial photogrammetry with unmanned systems, and vesselbased mobile LiDAR. Static photogrammetry is tested in the breakwaters of Punta Langosteira Port in A Coruña (Spain). It uses a camera for the acquisition of wave run-up on the structure. Image processing algorithms, based on binarization thresholding, and projective transformation, combined with the geometric data of the structure, provide the run-up height and detect the existence of overtopping events. Aerial photogrammetry using unmanned vehicles is tested in the breakwaters of Baiona Port (Spain). The photogrammetric restitution allows the generation of a dense point cloud with geometric information of the emerged part of the structure. Precision is evaluated and values of 0.026 m in standard deviation are obtained. Vessel-based mobile LiDAR system is used to obtain a point cloud from the Bouzas breakwaters in Vigo Port (Spain). The system provides an accurate point cloud from the structure. The accuracy of the dataset was validated using terrestrial LiDAR data. It shows errors lower than 0.09 m in 30 m range.
