An Estimation Method for Sound Speed Profile Based on Large Depth Array Multipath Delay

The sound speed profile (SSP) perturbations by oceanic dynamical processes are transferred to the sound field via acoustical models, introducing computational inaccuracies. Hence, an accurate estimation of the SSP holds significant importance. This letter introduces a method for SSP estimation based on the multipath delay structure of large depth vertical arrays. This approach capitalizes on the sensitivity of array's multipath delay structure to SSP perturbations and estimates SSP using a single explosive charge signal, thus minimizing the reliance on extensive acoustic data. The method primarily comprises three components: the establishment of a sound speed perturbation model, construction of a synthetic dataset, and parameter estimation based on the genetic algorithm. This letter employs the proposed model to generate foundational samples and maximizes the coverage of authentic SSPs, thereby enhancing the precision of SSP estimation. The acoustic observational SSP is obtained from deep-sea regions of the Western Pacific to compare with estimated SSP, the result of traditional method and publicly available online datasets. The results indicate that the method proposed in this letter achieves commendable accuracy, and the root-mean-square error (RMSE) between the estimated SSP and the observed SSP is only 1.3 m/s.