Resolving Power of Wave Gauge Array Installed in Lake Biwa

Abstract

In this paper, the resolving power of the wave gauge array for the measurement of directional spectra used in Lake Biwa is investigated, based on numerical simulation. The evaluation method with the best resolving power and the applicability region of the wave gauge array used are considered, evaluating approximate directional spectra of two-dimensional random waves with the known spectra generated by numerical simulation for the array through several computational methods of directional spectra and comparing between input spectra and output spectra. It is found that the least square method proposed by Borgman produces good results as does the function fitting method, so that for a frequency region containing the main energy of wind waves generated in Lake Biwa, better estimation of directional spectra is possible to be attained in applying these methods to the array.