Cross correlation matched field localization for unknown emitted signal waveform using two-hydrophone

Source localization is a crucial issue in underwater acoustics. Traditional matched field processing (MFP) use large vertical arrays to locate an underwater acoustic target. However, the use of the large arrays not only increases equipment and computational cost but also some problems such as element failures and array title degrades the localization performance. In this paper, the matched field localization method of using two-hydrophone is proposed for underwater acoustic pulse signals with unknown emitted signal waveform. Firstly, using the received signal of hydrophones and the ocean channel which can be calculated from an acoustic propagation model, the emitted signal for every grid location over search region can be estimated by using the least squares solution in the time domain. And then, the estimated signal is convolved with the ocean channel pulse for various trial source locations to generate the replica signal. Finally, matched field localization of using two-hydrophone for underwater acoustic pulse signals of unknown emitted signal can be estimated by comparing the difference between the cross correlation of the received signal and the cross correlation of the replica signal to construct the localization error function yielding the ambiguity surface of localization function. Theoretical analysis and numerical simulation demonstrate the effectiveness of the proposed matched field localization and the localization performance were analyzed under different signal to noise ratio (SNR) cases by simulation trial.