The invention relates to an unsteady-state sea wave direction spectrum
estimation method. The method comprises the steps of S1,
signal decomposition; s2, direction distribution calculation; s3, adaptively adjusting the
time domain analysis step length; s4, performing nonparametric kernel
estimation on the transient
wavelet distribution probability; and S5, direction spectrum
time domain adaptive reconstruction is carried out. In the
time domain analysis process of
wavelet analysis, a two-dimensional plug-in non-uniform bandwidth
algorithm is adopted to determine a data-adaptive two-dimensional non-uniform and non-parametric kernel function, the probability of different wavelets in a wave number-direction space is analyzed, the lateral propagation sea wave energy in the non-main wave direction is estimated, and the wave energy in the non-main wave direction is obtained. Therefore, the precision and the anti-
noise capability of the direction spectrum
estimation method are improved. In the time
domain analysis process of
wavelet analysis, a sea wave
signal fluctuation intensity detection
algorithm based on the frequency-direction-wave number three-dimensional change rate of wave
energy distribution is introduced, the
time duration of sea wave
signal sections is divided according to the fluctuation intensity, the time domain precision is adjusted, the calculation efficiency is improved, and meanwhile, the sea wave signals which rapidly change in the time domain are accurately captured. Measurement is avoided.