Source depth estimation in the presence of internal solitary waves based on matched mode function amplitude processing

In shallow water, the performance of the matched field processing (MFP) and matched mode processing (MMP) methods for estimating the source depth using the vertical linear array undergoes significant degradation in the presence of internal solitary waves (ISWs). This is because that acoustic pressure and mode amplitude served as the features in MFP and MMP, respectively, are highly sensitive to ISWs, resulting in a mismatch between the replica and the measured field. To address this problem, this paper introduces a feature, namely the mode function amplitude (MFA), which is less susceptible to ISWs and contains information about the source depth. Based on MFA, we propose a matched mode function amplitude processing method, which enhances source depth estimation in shallow water under the influence of ISWs. The simulation results show that this method achieves significantly higher accuracy and stability than MFP and MMP.