分析海浪方向谱的扩展本征矢方法　Ⅱ.方法的验证、比较和应用

AN EXTENDED EIGENVECTOR METHOD FOR ESTIMATION OF DIRECTIONAL SPECTRA OF SEA WAVES Ⅱ. VERIFICATION, COMPARISON AND APPLICATION OF THE METHOD

采用Longuet－Higgins形式的方向分布函数作为已知谱，用模拟数据检验了作者所提出的估计方法EEV的合理性，并与扩展最大似然方法（EMLM）及Lygre等（1986）的最大熵方法（MEM）作了比较．在验证和比较中，使用纵摇-横摇浮标、星形阵列和CERC阵列作为复合阵列。计算表明，EEV优于EMLM和MEM。最后将EEV和EMLM两种方法应用于仪器阵列的外海观测数据，得到了比较合理的海浪方向谱。

In Part Ⅰ.of the paper, an extended eigenvector method (EEV) for the estimation of directional spectra of sea waves was derived. The EEV is verified and compared with the extension of ,the maximum likelihood method (EMLM) and the maximum entropy method (MEM) of Lygre et al. by numerical simulations in the present paper. In the numerical simulations, the directional spreading functions of Longuet-Higgins type are employed as input and the existence of noise background in input is considered. Three types of pitch/roll buoy, star and CERC of wave probe array were adopted. The results of the simulations show that the EEV is superior to the EMLM and the MEM, and is especially .competent for sea waves with high background noise and narrow angular spread. The EEV and the EMLM methods and 4 probes were used for the estimation of directional spectra from field observation data obtained at an oil platform. The estimated dirctional spectra are reasonable and reliable.