An expectation-maximization based single-beacon underwater navigation method with unknown ESV

摘要

Navigation performance in a single-beacon underwater navigation system considerably depends on the accuracy of the slant-range measurement. Ranges are usually obtained based on a presumed or known effective sound velocity (ESV). Because it is difficult to accurately determine the ESV between the pinger and the receiver, traditional methods are usually affected by large-range measurement errors that lead to large positioning errors. In this study, we use the expectation maximization (EM) method, which is widely used for parameter identification, to estimate the unknown ESV by treating it as a model parameter. We propose an EM-based, single-beacon navigation method that incorporates the Kalman filter into the EM frame. Numerical examples using simulated and field data indicate that navigation accuracy can be significantly improved when the proposed EM-based method is implemented, and the estimated ESV is in good agreement with its true value. (C) 2019 The Authors. Published by Elsevier B.V.