An Investigation into the Use of Cepstral Analysis in the Decomposition of Ocean Waves.

Cepstral analysis decomposition techniques work extremely well with the pusle-shift P-M generated combined wave model and not so well with the forward-shift P-M generated combined wave model. Problems exist with identification of delay time as well as with decomposition of the combined wave when cepstral analysis techniques are applied to P-M generated wave-models which vary tau andor the reflection coefficient, alpha, as a function of frequency. More research is required before this decomposition technique can be successfully applied to real-world ocean waves. It may never work for decomposition of combined waves for which the reflected wave frequency information is altered by the structure and no longer is the same as the incident wave, such as occurs with shorelines and many breakwaters. Of the three cepstrum types examined, the power cepstrum is the best indicator of delay time between incident and reflected waves. The phase cepstrum does not seem to offer much information other than reinforcement or possible validation of the power cepstrum information.