深海声影区时频谱干涉结构与声源定位

Interference patterns and source localization in the shadow zone of deep water

被动声呐探测位于深海声影区的水面舰船辐射噪声时,接收信噪比通常较低,导致声源被动定位方法的性能较差。针对这一问题,提出一种利用接收信号时频谱干涉结构的声源距离和径向速度联合估计方法。首先根据射线声学理论,建立时频谱沿频率轴和时间轴的干涉条纹周期与声源距离和径向速度的关系,然后对接收信号时频谱进行二维傅里叶变换和多频带处理以估计上述干涉条纹周期,最后解算声源距离和径向速度。仿真和海试数据处理结果表明,相比于现有利用接收信号自相关的声源距离估计方法,该文利用时频谱二维傅里叶变换的声源定位方法具有较好的稳健性,比较适用于低信噪比条件下的声源被动定位。

Passive sonar usually has a low signal-to-noise ratio(SNR)when detecting the radiated noise from a surface ship in the shadow zone of deep water,resulting in poor performance of passive localization methods.In order to solve this problem,a joint estimation method of the source range and the radial velocity based on the interference structure in the received spectrogram is proposed.The relationship between the periods of interference fringes along the frequency axis and the time axis in the spectrogram and the distance as well as the radial velocity of the source isfirst established.These interference periods are then estimated by applying two-dimensional Fourier transform(2-D FT)and multiband processing to the received spectrogram.The source range and the radial velocity arefinally calculated.The simulations and the sea experimental results show that the proposed localization method using 2-D FT of the spectrogram has better robustness than the existing range estimation method based on the autocorrelation of the received signal.Therefore,it is more suitable for passive source localization under low SNR conditions.