METHOD FOR ESTIMATING DIRECTIONAL WAVE SPECTRUM IN INCIDENT AND REFLECTED WAVE FIELD

Abstract

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.