... performed in wave basin laboratories is often applied. In such cases, knowledge about the wave conditions is of great significance. For validation of the wave condition in such tests, different methods for estimation of the directional wave spectra may be applied. However, different assumptions are imposed...

... 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...

... non-dimensional roughness length sea surface donelan wind speed cross swell case toba drag coefficient ebuchi coefficient suzuki roughness length university swell case variation kyoto university directional wave spectra wind speed region wind stress ABSTRACT The drag...

... define a suitable choice of the parameters prior to the wave estimation, thus reducing the computational effort without significantly increasing errors in the estimations. bayesian inference frequency variation upstream oil & gas spectrum spectra procedure directional wave spectra...

... 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...

... of altimeter wave heights from ERS2 only. A statistical analysis of the wave heights obtained with different runs at crossover locations of JASON-1 and ENVISAT is presented and shows the best estimate when using the ASAR spectral information. INTRODUCTION The possibility of using directional wave spectra...

... 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...

... the impact of the assimilat ion is more significant for the low frequency part of the wave spectrum. The comparison with existing altimeter data from ERS2 has permitted on the one hand to validate the real ASAR directional wave spectra, and on the other hand to estimate the efficiency of the assimilation...

... 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 and coast...

... 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...