X-Band Radar as a Tool to Determine Spectral and Single Wave Properties

The Wave Monitoring System WaMoS II was developed for real time measurements of directional ocean waves spectra to monitor the sea state from fixed platforms in deep water or coastal areas as well as from moving vessels. The system is based on a standard marine X-Band radar used for navigation and ship traffic control. WaMoS II digitises the analogous radar signal and analyses the sea clutter information to obtain directional wave spectra from the sea surface in real time even under harsh weather conditions and during night. Spectral sea state parameters such as significant wave height, peak wave period and peak wave direction both for wind sea and swell are derived. Within the EU funded project ‘MaxWave’ and the German project ‘SinSee’ new algorithms were developed to determine sea surface elevation maps from radar images which are used to investigate the spatial and temporal evolution of single waves simultaneously. In this paper a short overview describes the calculation of surface elevation maps and the detection of individual waves. Considering two case studies, the results of spatial single wave detection and corresponding temporal single wave properties are compared and discussed. Individual wave parameters derived from radar images are compared to individual waves measured by a buoy. An application of the method to characterise extreme sea states is discussed.