基于双水听器的浅海水声目标深度分类方法

Underwater acoustic target depth classification method based on dual hydrophones in shallow water

针对现有水声目标深度分类方法存在阵元数目要求较高、频率适用范围有限、信噪比要求较高的问题,基于有效深度模型,利用不同深度处双水听器采集的声压信号计算出声压互谱信号,根据声压互谱信号的深度分布特征,提出了适用于低信噪比工况的浅海水声目标深度分类方法.利用声压互谱有功分量的符号分布进行目标深度分类,仿真分析了接收深度、声源频率、信噪比、线谱稳定性、声速分布对算法性能的影响,验证了算法的可行性与稳健性.算法适用于线谱频率激发三阶简正波的情况,算法的频率适用范围得到进一步扩展,在低信噪比工况下仍能获得较好的深度分类效果.

The existing underwater acoustic target depth classification methods have a limited frequency range and set strict requirements for the number of array elements and signal-to-noise ratio.Aiming at the above three problems and using the pressure signals collected by the hydrophones at different depths,we obtain pressure cross-spectrum signal based on effective depth model.According to the depth distribution characteristics of pressure cross-spectrum signal,a novel underwater acoustic target depth classification method is proposed which is suitable for low signal-to-noise ratio condition.Using the sign distribution of pressure cross-spectrum active component,target depth classification can be realized.The effects of different receiving depth,source frequency,received signal-to-noise ratio,line spectrum stability and sound speed profile on the performance of the algorithm have been studied in this paper.The feasibility and robustness of the algorithm have been verified by simulation.The algorithm is suitable for the case where line spectrum frequency excites three normal modes,and the frequency range of the algorithm is further expanded.The algorithm can also obtain ideal depth classification results under low signal-to-noise ratio conditions.