船辐射噪声高阶谱分析和标记图

实验数据揭示了一些舰船辐射噪声通过在频带上连续排列的窄带滤波器组后,各频道中的幅度调制很相似,这是舰船噪声的一个很有应用前景的目标特性。文章还研究了用高阶谱高阶统计的信号处理工具来提取和保留幅度周期调制的相位信息,并给出了计算机模拟结果,实际船噪声结果和具体提取方法。利用这些相位信息和双谱的幅度信息可以重建周期调制信号,并称这个重建波形为这条船的标记图。最后调查了三条船的标记图与本船及不同船的实际幅度调制之间的互相关系数,本船的互相关系数要比不同船的互相关系数大许多。

Ship-radiated noise analysis with higher-order spectrum and its signature

Higher order statistics is used to extract the phase information of ship-radiated noise's periodical modulation waveforms.The results from real date analysis are compared with computer simulation and a phase extraction method is presented.The periodical modulation waveform is reconstructed from its bispectrum's phase and amplitude information,and the reconstructed signal is called'Signature'of that ship.The correlation function between three ship's signatures and their real modulation waveforms are given out.It is clear that normalized correlation between the signature and real modulation waveform of the same ship are much higher than that between different ships.One characteristic of ship-radiated noise which has a broad application prospect is discovered,ie.modulation waveform in different frequency bands of ship-radiated noise are very much alike.