Comparative laboratory test on methods for directional wave spectrum analysis

A review of theoretical ideas and problems in directional spectrum analysis is first presented. Some specific methods are briefly described. These include a Fourier Series - Maximum Entropy Method, a Maximum Likelihood Method, a Particle Velocity Method and a Spatial Correlation Method. They are applied in analysis of directional wave measurements made in a wave basin. The results show fairly good agreement, both between methods and with input, in the rough spectral structure, while details show more scatter. The scatter is probably due to both differences in the resolution, natural statistical variations, the wave generation method, and also due to errors introduced by the signal processing.