28 research outputs found
Bestimmung der Wassertiefe und der oberflaechennahen Stroemung mit einem nautischen Radar
The Wave Monitoring System (WaMoS) uses a nautical radar as a sensor to measure the wave spectrum and other parameters. In the threedimensional frequency-wavenumber space the spectral energy of surface gravity waves is located on a surface defined by the dispersion relation (dispersion shell). The dispersion relation is used as a spectral filter to seperate the imaged spectral wave energy from clutter noise. In shallow waters the form of the dispersion shell is influenced by the near surface current and the water depth. In this case the knowledge of the actual water depth is of great importance for the spectral filtering. A method was developed to estimate the water depth and the near surface current in once by analysis of radar image sequences. For this the measured spectral wave energy is suited to the dispersion shell by an iterative least-squares algorithm. The method's function and limits were tested by simulations. Also the method was validated on measured data. (orig.)Available from TIB Hannover: RA 3251(98/E/60) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman