The DIME collaborative project, which focuses on improving knowledge of sea states in the event of storms, includes an unprecedented operation that began in December 2017 near the island of Ushant. The principle? To use La Jument lighthouse as an experimental device on a 1:1 scale. A current profiler located at the foot of the building and a wave buoy anchored 2 km to the west provide in situ information on the waves and surrounding currents. State-of-the-art equipment has also been installed on the lighthouse gallery: a stereoscopic camera system allows the waves to be reconstructed in three dimensions, and a radar is used to map the wave field on a larger scale. Accelerometers quantify the movement of the building under the effect of the waves. Three pressure sensors have been installed on the lighthouse façade to determine the forces exerted by the waves.
A measurement campaign is carried out every winter. This week, a mission is organised on the lighthouse to install new boxes for the stereo-video system installed at the top of the building. The aim: to avoid vibrations and gain in precision. After exploitation and analysis, the data acquired will make it possible to improve the characterisation of extreme and breaking waves, an essential element in the optimisation of ORE systems and therefore their competitiveness in terms of costs.
Photo credit: France Energies Marines