Sea state

the emblem of the BSH

Sea state


The parameters


Significant Wave Height

The significant wave height Hs is often called the mean wave height although it corresponds to the mean value of only one third of the waves, that with the highest waves (H1/3). In the evaluation of data, the significant wave height is computed by the equation:
Gleichung Wellenhöhe
with E(f) the energy per frequency band df. The significant wave height may be considered a comparative value for ship observations, which are estimates.

Periods, frequencies

The zero crossing period Tz is the mean period of all excursions of the water surface cutting the mean sea level line. It is slightly shorter than the mean period Tm. The peak period normally is the longest. It is the period of the absolute spectral energy maximum.

Peak period Gleichung Peakperiode
Mean period Gleichung mittlere
Zero crossing period Gleichung
nth moment (mode) Gleichnung n-tes Moment

Wave direction

The direction indicated is that of the absolute energy maximum.


 © 2018 Bundesamt für Seeschifffahrt und Hydrographie Last Update: Apr 19, 2013 6:02:34 PM  
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