New solution for directional wave analysis in reflective wave fields

A new and robust method for computing the directional wave spectrum is pres ented that is valid either in the presence or the absence of phase-locked r eflections. The method is a parametric solution to the directional wave spe ctrum. Unknown parameters are evaluated with the aid of a genetic algorithm . The routine works on the principle of optimizing a fitness parameter that is a function of the difference between the measured and theoretical (para metric) cross spectra. The theoretical cross spectrum is expressed in terms of the principal wave direction, a spreading parameter, a reflection coeff icient, and the reflection line distance. This method forms a robust and re peatable solution for the computation of directional wave spectra and the e stimation of unbiased frequency dependent reflection coefficients. The meth od has several advantages over existing methods. These include the fact tha t valid solutions can be obtained, in the presence or absence of wave refle ction, close to or far from the reflector and without a prior knowledge of the reflection line position.