南海北部海域声速剖面水平变化环境声学层析

Range dependent sound speed profile inversion in the northern area of the South China Sea

为获取水平变化的海水声速分布,在等效平均海水声速反演基础上,提出了一种声速剖面水平变化环境声学层析方法。首先利用经验正交函数结合匹配场处理方法反演不同距离下的等效平均声速剖面,进而通过逐步迭代重构出随水平距离变化的声速场分布,并通过数值仿真及海上实验两方面验证了声速剖面水平变化环境声学层析方法的可行性及其准确性。结果表明:声速剖面水平变化环境声学层析结果与实验测量声速剖面均方根误差小于0.8 m/s,利用声传播信号基本能较为准确地重构出随距离水平变化的海水声速分布,为进一步层析中尺度三维结构及声呐水声环境保障应用奠定了基础。

A range dependent tomography method is proposed to obtain the range dependent Sound Speed Profile(SSP).A segmented matched-field inversion method based on Empirical Orthogonal Functions(EOFs)is used to invert the equivalent average SSP.The SSPs of segment points are calculated by an iterative method and the horizontal distribution of the SSP is obtained.Both numerical simulation and experimental acoustic data from the South China Sea use to validate the proposed method.The results demonstrate that the range dependent SSP can be obtained correctly with the Root Mean Square Error(RMSE)of 0.8 m/s.The inverted SSPs are consistent with the expendable bathythermograph(XBT)measurements at each site.The range dependent tomography method is meaningful for mesoscale structure inversion and sonar application.