深海直达声区水下声源距离深度联合估计

Combined Estimation of Range and Depth for Underwater Source in the Direct Zone in Deep Water

深海直达声区声场存在明显的多途结构,可用于水下声源被动定位。本文根据一次南海实验获取的数据,研究基于双水听器接收信号互相关函数和单水听器接收信号自相关函数的水下声源距离深度联合估计方法。首先假设声源深度位于50m^300m之间,根据双水听器互相关函数提取直达波到达时间差估计水下声源距离,然后根据距离估计结果以及单水听器自相关函数提取的直达波与海面反射波时延差估计水下声源深度,最后计算声源深度估计结果的平均值再与双水听器互相关函数结合得到更为精确的距离估计结果。结果表明,采用此方法估计的水平距离相对误差在10.5%以内,声源深度相对误差小于13.3%。

The sound field of direct zone in deep water has obvious multi-path structure, which can be used for passive localization of underwater sound source. Using the data obtained from an experiment in the South China Sea, a combined source localization method for underwater target in deep water is proposed, which estimates the range based on the cross-correlation function of signals received by two vertical hydrophones and depth from the autocorrelation function of signals received by a single hydrophone. Firstly, the arrival time of the direct wave is extracted from the cross-correlation function to estimate the source range by assuming the source depth range from 50 m to 300 m. Then, the delay time between direct wave and surface reflect wave is extracted from the auto-correlation function of one receiver to estimate the sound source depth combining the range estimation result. Finally, a more accurate range estimation can be derived by combing the average value of the depth estimation result and the cross-correlation function. The results show that the relative error of range estimation is within10.5 %, and the relative error of sound source depth estimation is within13.3 %.