Investigation on the Partitioning of Sea Spectra

This paper aims at evidencing the strengths and weaknesses of the methods available in the literature for the separation of different sea spectral components associated to complex sea states where both wind and swell seas are present. The paper focuses on the methods which rely just on the sea level measurement without the need of wind direction information. Particularly, a renown and effective method has been tested on different sea state combinations and the results are discussed, highlighting the need of developing methods which do not just find a frequency separation between sea wind and swell components but are also able to separate the two contributions when they are close each other. To this purpose an index is proposed and tested based on Power Spectral Density integrals, that demonstrates to be effective in the seven tests cases considered.