Effect of Different Wave Crest Definitions on Wave Crest Statistics

In this paper, the spatial distributions of wave crest are obtained on the basis of the numerical simulationn of 3-D random waves, and the crest distributions are used to examine the correctness of the crest characteristic values (including the crest length and direction angle) obtained by two crest defining methods. One method is to define the longest distance between two points at the crest boundary as the crest length, and the other is to fit an ellipse to the crest area and take the major axis of ellipse as the crest length. It is shown from the comparison between the crest length statistics obtained by the two methods that the two kinds of crest characteristic values are basically consistent with each other, especially the statistics of crest length are quite close to each other, and the accuracies of their statistics are about the same, which indicates that the effect of two crest defining methods on the crest length statistics is small.