海浪资料的平滑和海浪谱谱矩估计

Partial Averaging of Wave Data and Estimates of Spetral Moments of Wind Waves

基于海浪谱估计理论,按谱估计方法导出了离散波面记录平滑处理后的谱形式,并计算了由各阶谱矩表示的谱宽度。指出平滑后的离散波面记录产生了新的随机过程,它们和原离散波面记录的内部结构和外部特征是完,ε7=1-m27几乎不受平滑(N=2,N=3)的影全不同的。但高阶矩表示的无因次谱宽度,即ε5=1-m25m6m8m4m6响,和原始谱的对应值相吻合。通过离散波面记录求导处理得波面速度谱,与理论转换得速度谱结果几乎完全一致。

In this paper, based on the theory of estimation of wind wave spectra, the spectral forms of discrete wave data after partial averaging treatment are derived according to the methed of spectral estimation, and the spectral widths expressed by different spectral moments are computed. It is pointed out that the partially averaged discrete wave data produce new random processes, which are completely different from the original discrete wave data in the internal construction and external characteristics. However, the non-dimensional spectral widths expressed by high order moments ε_5=1-m~~2__5m_4m_6 and ε_7=1-m~~2__7m_6m_8are in agreement with the corresponding values of original spectra,and are not influenced by partial averaging. The spectra of wave velocity obtained by derivation of discrete wave data agree with the spectra of wave velocity obtained by theoretical transformation.