波形未知的水声脉冲信号双阵元相关匹配场定位

Matched field localization using correlation of two-hydrophone underwater acoustic pulse signals with unknown waveform

针对波形未知的水声脉冲信号,提出一种基于双阵元的相关匹配场定位方法.通过水听器所接收到的信号和声场传播模型算得的海洋信道脉冲响应,对所划分的搜索网格区域采用时域最小二乘的方法获得每个网格点位置上发射信号的估计值.由估计出的发射信号与信道脉冲响应卷积产生相应的拷贝场信号;通过计算双阵元接收信号的相关函数与拷贝场信号的相关函数之间的误差,构造定位函数的模糊表面,实现双阵元对波形未知的水声脉冲信号的匹配场定位.采用2种声传播模型分别对连续波(CW)脉冲信号与线性调频(LFM)脉冲信号进行仿真实验,结果表明,该方法不受信号形式和声传播模型的限制,克服了传统匹配场处理由于阵元个数过少而导致的定位模糊表面旁瓣过高的问题,具有较好的定位效果.

The correlation matched field localization method is proposed for underwater acoustic pulse signals of unknown emitted signal waveform based on two-hydrophone.Using the received signal of hydrophones and the ocean channel pulse response which can be calculated from an acoustic propagation model,the emitted signal for every grid location over search region can be estimated by employing the least squares solution in the time domain.The estimated signal is then convolved with the ocean channel pulse response for various trial source locations to generate the replica signal.Finally,the correlation matched field localization of the two-hydrophone for underwater acoustic pulse signals of unknown emitted signal waveform is realized by comparing the difference between the cross correlation of the received signal and the cross correlation of the replica signal to construct the ambiguity surface of localizer function.Two acoustic propagation models are used to test the proposed method for continuous wave（CW） pulse signal and linear frequency modulation（LFM） pulse signal,respectively.Simulation results show that the proposed method is not restricted by the type of pulse signals and acoustic propagation model.It overcomes the problem of the high sidelobes of the traditional matched field processing due to lack of the number of hydrophones and provides high location accuracy.