舰船噪声通过特性过零数特征的分析与应用

在正常巡航条件下，舰船沿纵向分布着三个具有不同功率谱特征的声辐射部位。通常，目标舰船距离观测点很远时，舰船可被视为一个点声源，但舰船距离观测点很近时，就不能再被视为点声源，而应被视为体积目标更为合理。分析了舰船做为体积目标时辐射噪声功率谱的纵向特性，利用舰船辐射噪声波形的过零点数分布，构造了舰船噪声通过特性的过零数特征矢量，为舰船目标识别分类研究提供了一种新的特征量，并应用BP网络做了分类实验，实验证明：过零特征可以作为水中目标识别的重要依据，是一种有效的分类方法。

Analysis and Application of Ship-radiated Noise's Zero-crossing Number

The ship-radiated noise caused by three longitudinal locations has different power spectrums at cruise speed.At long distance(the far field),a ship can be considered to be a dot sound source,while at short distance(the near field),it is more retional that the ship should be considered to be a volume target.This paper studies the longitudinal distribution of ship's radiated noise power spectrum as a volume target.A new feature vector of ship-radiated noise based on wave structure is presented.BP neural network is applied to ship-radiated noise taken from sea trial to classify the type of ship.The experimental results denote that the feature vector of ship-radiated noise is satisfactory.