Autoregressive (AR) bispectra of wind waves in the coastal zone

The paper examines the second-order non-linearity of the wind waves by bispectral analysis based on non-parametric (conventional) and parametric approaches. The parametric technique is presented by model that is in the class of autoregressive (AR) processes. The wave measurements are taken at depth 1.6 m in the coastal zone of the Bulgarian part of the Black Sea. The bispectral estimates are evaluated by aforementioned approaches and subsequently are compared in order to establish whether AR modelling is applicable to analysis of the nonlinear wind waves propagating in the coastal zone. The results show good agreement between conventional and parametric estimates.