The ship radiated noise is analyzed and its 4 features are extracted from the envelop spectrum . the envelope of ship noise waveform can be demodulated utilizing hilbert transform , and the spectrum components with line rotation frequency of propeller shaft are extracted effectively by bispectrum , 1 ( 1 / 2 ) spectrum and 2 ( 1 / 2 ) spectrum analysis 對(duì)于通過(guò)希爾伯特變換解出的艦船輻射噪聲包絡(luò)信號(hào)進(jìn)行高階統(tǒng)計(jì)量分析,有效地提取出了艦船噪聲的雙譜、 11 / 2維譜、 21 / 2維譜等方面的特征。