... ABSTRACT Directional wave spectra are of importance for many practical applications. Previous studies show that the wave spectral densities at a given point are correlated with the local or remote wind field. This feature can be used to predict the wave spectrum empirically. In this study...

... spectral data in long period measurements. Wind and wave data observed at a coastal tower operated by Shirahama Oceanographic Observatory of Disaster Prevention Research Institute, Kyoto University, Japan, together with data sets observed by Suzuki et al. (2002) are used. The directional wave spectra were...

... in the estimations. KEY WORDS: Bayesian estimation, Directional wave spectra, hyperparameters, ABIC INTRODUCTION In recent years, many research groups have addressed the problem of directional wave spectrum estimation from the record of vessels 1st order responses ( (Nielsen and Iseki, 2010), (Iseki, 2011), (Simos...

... in the recent past (e.g. Iseki and Terada, 2002). One of the most important problems for the systems was to get information about directional wave spectra. Based on the assumption of linearity between waves and ship motions, some studies tried to estimate directional wave spectra using ship motion data (e.g...

... ABSTRACT: In this study, a new technique to estimate directional wave spectra with respect to encounter waves of ships based on ship motions data is introduced. Firstly, the ship motion is analyzed by a Time Varying AutoRegressive modeling procedure, and cross spectra of the ship motion data...

... spectra and wind direction. The simultaneously observational technology for sea surface currents by HF radar sea-echo Doppler spectrum has already been established and applied into practical use. Nonetheless, the estimation of directional wave spectra remains unexplored, and limited to theoretical aspect...

...Validation and Assimilation of ENVISAT ASAR Directional Wave Spectra in Wave Model WAM Lotfi Aouf(1), Jean-Michel Lefèvre(1), Danièle Hauser(2) and Bertrand Chapron(3) (1) Météo-France, Division of Marine and Oceanography, Toulouse, France. (2 )CETP/IPSL/Université de Versailles Saint-Quentin...

... ABSTRACT An online procedure for estimating directional wave spectra for marine vessels is proposed. The procedure is developed as a subsystem of onboard marine guidance equipment. To simplify the system, the hull of a ship is regarded as a wave sensor and time history data of ship motions...

...Optimization of the Assimilation Scheme of Directional Wave Spectra in Wave Model WAM: Application to Real ASAR -ENVISAT Wave Spectra Lotfi Aouf(1), Jean-Michel Lefèvre(1) and Danièle Hauser(2) (1) Météo-France, Marine Forecast Service, Toulouse, France. (2 )CETP/CNRS/Université de Versailles Saint...

... directional wave spectra by EMEP method (Hashimoto, 1997). Based on directional wave spectra the data sets can be separated into Case 1 and Case 2, where Case 1 is only swell and wind waves, and Case 2 is existing a lot of component wave. It was shown that conditions of Case 2 existed by form of a bay...

... ABSTRACT New techniques are introduced into the Bayesian modeling procedure to estimate directional wave spectra based on ship motion data. In the proposed method, the triple-valued function problem in following seas is strictly taken into account and the optimum solution is obtained from...

... for the nonlinear energy exchanges among sets of waves of different frequency and directions. experiment evolution wave train type ii instability wave instability water depth gravity wave ii instability energy transfer shallow water mclean directional wave spectra unperturbed wave shallow-water...

... for Estimating Directional Wave Spectra from Heave-Pitch-Roll Time Series E.K. Skarsoulis and G.A. Athanassoulis National Technical University of Athens Athens, Greece Abstract The joint statistics of averaged sample auto- and cross-spectra from a heave-pitch-roll time series is studied. It is found...