舰船辐射噪声节拍功率增率特征提取

Feature extraction on power increase rate of ship radiated noise tempo

舰船辐射噪声节拍的音色特征是水下目标识别的重要依据,其与节拍能量的变化相关。首先采用短时傅立叶变换对舰船辐射噪声进行时频分析,然后根据时频能量分布图,分别计算节拍能量最强和最弱处累积功率谱,功率增大率反映了节拍的音色特征,是舰船辐射噪声的重要特征。通过实验证明:与以往的功率谱特征相比,节拍功率增率特征和功率谱特征联合识别能有效的提高识别率。

Timbre feature of ship radiated noise tempo is important basis of underwater target classification.It is related to the energy change of tempo.Ship radiated noise is analyzed by short time Fourier transform.According to time-frequency energy distribution spectrum,power spectrum of strongest and weakest tempo energy are calculated.Power increase rate reflects the timbre feature of tempo,so it is an important feature of ship radiated noise.It has been proved by experiment that the recognition rate is increased by combination of power spectrum feature and power increase rate feature,compared with traditional power spectrum feature.