A study of bispectrum from narrow band nonlinear surfaces

Surface bispectrum are obtained from a computer generated skewed surface profile based on a narrow band representation of a nonlinear surface model. Then basic properties are analyzed and summarized. Consistent with the definition and properties of the bispectrum, a Gaussian and two exponential decay functions are tested as possible representations for the asymmetric part of the surface bispectrum. This part has been found to be important in backscattering. Of the three proposed models, the exponential decay functions are found to be in better agreement with the simulated bispectrum in both bandwidth and wavenumber decay rate. The Gaussian model exhibits larger bandwidth and hence does not agree with the simulated bispectrum