中文摘要：

对水下目标实施被动定位是水声学中的一个关键问题.传统的匹配场定位技术结合了水声传播规律的特点,利用拷贝声场与测量声场进行匹配,可获得较为准确的定位效果,因而被视为是一种良好的定位技术.但是传统匹配场处理使用大的垂直阵列来确定水下声源的位置,不仅增加了系统的开销,而且易受诸如阵倾斜以及阵元失效等问题.同时,传统的匹配场定位当阵元个数较少时,会导致定位结果输出具有较高的旁瓣,进一步恶化了定位性能.本文以未知波形的水声脉冲信号为对象,提出一种利用两个水听器进行匹配场定位的方法.该方法首先借助单一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估计每个网格点位置上的发射信号;由估计出的发射信号与海洋信道脉冲响应,通过时域交叉卷积的方法,产生相应的拷贝场信号;通过计算单一水听器的接收信号与拷贝场信号之间的误差,建立代价函数,构造定位函数的模糊表面,实现利用两个水听器对波形未知的水声脉冲信号的匹配场定位.通过理论分析和对浅海环境的一个宽带脉冲信号进行数值仿真证明了所提方法无需已知发射信号的波形,定位模糊表面的峰值清晰,且旁瓣较低,具有显著的定位性能.

英文摘要：

Passive source localization is a crucial issue in underwater acoustics.Conventional matched field processing（MFP）,which takes into account the propagation from source to receivers,using pressure field replicas to match the measured signals to obtain the more accurately localization results,therefore it have been regarded as a good localization technique.However,Conventional MFP uses large vertical arrays to locate an underwater acoustic target,which not only increases equipment and computational cost but also subject to some problem such as element failures and array title.At the same time,the sidelobes of the ambiguity surface of conventional MFP are higher when the number of hydrophones are quite small,which degrade the localization performance.In this paper,a matched field localization algorithm using two-hydrophone for underwater acoustic pulse signal with unknown emitted signal waveform is proposed.The localization algorithm was firstly analyzed from time domain,using the received signal of a single hydrophone 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 square solution in the time domain.The resulting the estimated signal is then cross convolved with the ocean channel pulse response for various trial source location to generate the replica signal.Finally,matched field localization of using two-hydrophone for underwater acoustic pulse signal with unknown emitted signal waveform can be realized by comparing the difference between the received signal and the replica signal of a single hydrophone to construct the localization error function yielding the ambiguity surface of localization function.Theoretical analysis and numerical simulation results from a shallow-water environment for broadband pulse signals demonstrate the proposed matched field localization algorithm require no priori knowledge of the source signal waveform and the ambiguity surface has a