Bundesanstalt für Gewässerkunde (BfG)
Department M1 - Hydrometry and Hydrological Assessment - of the Federal Institute of Hydrology has developed an operationally usable, low-maintenance system for determining the water level (resting water level (DIN 4049)), the sea state and the direction of the sea state. It consists of four radar sensors that measure the distance between the research platform and the water surface. The system has been successfully in use since 2013.
The radar sensor allows a very accurate and fast sampling of the water surface at a measuring point, which can be used to determine different sea state parameters (water level, wave period, significant wave height, etc.). Due to the non-contact measuring principle, the system is particularly suitable for operational use in coastal and offshore areas, as the influence of the measurement by marine vegetation or damage to the measuring system by wave impact unlike touching systems can not occur.
By extending the sea state measuring system with three other radar sensors to an array, the measuring system is also used to determine the direction of the sea. The direction information is thereby obtained from the combination of the simultaneously measured at the four positions data series. These are especially needed for the design of coastal structures, as well as for the planning of offshore work (possibility of overhauling the technicians from and to the ship).