浅海中利用单水听器的声源被动测距

Passive source range estimation with a single receiver in shallow water

针对浅海声波导中远距离脉冲声源被动测距问题,提出了一种利用单水听器接收信号自相关函数进行warping变换的声源被动测距方法。理想水下声波导中,接收信号warping变换输出的傅里叶变换频谱中具有不变性频率特征,即与声源距离无关的各简正波截止频率;信号自相关函数中不同简正波相干成分也存在不变性频率特征;推导了未知声源距离时特征频率提取值与不变性频率特征之间的近似关系式。这些规律可推广到实际浅海声波导,并用于声源被动测距。利用声场计算模型来提供具有不变性频率特征的频谱,对2011年12月北黄海海域水声实验中单水听器接收的脉冲声数据进行了处理,验证了方法的有效性,测距结果和实际距离符合良好,平均测距误差在10%以内。

An approach for long-range passive impulsive source ranging with a single receiver in shallow water is derived, which utilizes the frequency spectrum of the warped signal autocorrelation function via warping transform. In an ideal waveguide, the frequency spectrum of the warped signal owns invariable frequency features i.e. modal cut-off frequencies. There also exist similar invariable frequency features for the warped signal autocorrelation function due to modal interference. The approximate relation formula between the characteristic frequency at an unknown source range and the intrinsic frequency extracted by the time warping transform is derived. These rules can be generalized to an actual shallow water waveguide and applied to passive source ranging. Employing an acoustic model to offer the invariable frequency spectrum features, the impulsive signal data collected by a single hydrophone in the North Yellow Sea in December 2011 are analyzed to verify the proposed source ranging approach. The estimated ranges are in good agreement with the measured, and the mean relative error of range estimation is less than 10%.