Open AccessMETHOD FOR ESTIMATING DIRECTIONAL WAVE SPECTRUM IN INCIDENT AND REFLECTED WAVE FIELD
Author(s) -
Masahiko Isobe,
Kosuke Kondo
Publication year - 1984
Publication title -
proceedings of conference on coastal engineering/proceedings of ... conference on coastal engineering
Language(s) - English
Resource type - Journals
eISSN - 2156-1028
pISSN - 0589-087X
DOI - 10.9753/icce.v19.32
Subject(s) - spectrum (functional analysis) , phase (matter) , spectral density , reflection (computer programming) , reflection coefficient , optics , field (mathematics) , physics , computational physics , electromagnetic spectrum , statistical physics , acoustics , mathematics , statistics , computer science , quantum mechanics , pure mathematics , programming language
The relationship between the directional spectrum and the crosspower spectra in an incident and reflected wave field differs from the situation with no reflected waves because the phase lag between the incident and reflected waves is not random. Extra terms, which may be called phase interaction terms, exist. Hence standard methods for estimating the directional spectrum are not applicable. In the present study, the MLM is modified for this situation and the method is termed the MMLM (Modified Maximum Likelihood Method). The validity of the MMLM is examined by numerical simulation. The results indicate that the MMLM has a high resolution power. Formulas to determine the reflection coefficient are derived and their accuracy and suitability are examined.