四阶累积量对角切片法提取舰船辐射噪声特征

Features extraction of ship radiated noise by fourth order cumulant diagonal slice

从理论上分析了四阶累积量的特性,由此将四阶累积量分为三部分:第一为三次频率（相位）耦合部分的四阶累积量,第二是双对频率（相位）耦合（ω1+ω=ω3+ω4）部分的四阶累积量,第三为无上述两种耦合部分的四阶累积量。在此基础上,用四阶累积量的对角切片分析并提取了实际舰船辐射噪声的三次频率（相位）耦合特征、双对频率（相位）耦合特征以及子带“能量”分布特征,并将这些特征送入神经网络分类器对舰船进行分类识别,取得了A,B,C三类舰船正确识别率分别为92.5％,92.7％,88.6％的良好效果,从而验证了该方法的有效性和实用性。

After analyzing Fourth Order Cumulant (FOC) of harmonic signals, we divide the FOC into three parts. One is the FOC of the cubic frequency (phase) coupling components of the signals. The second is the FOC of the double frequency (phase) coupling components of the signals, which is proposed by us first. The last is the FOC of the rest components of the signals. On the bases of the study, the FOC diagonal slice is used to extract the cubic frequency (phase) coupling feature, double frequency (phase) coupling feature and the 'sub-band energy' feature of ship-radiated noise. In terms of the features, the three type ships are classified by means of artificial neural network. The correct classification rates of A, B and C ships are 92.5%, 92.7%, 88.6%, respectively. The results shows the method is effective and practical.