A new approach to three-dimensional underwater tracking that considers acoustic medium effects

This paper presents a three-dimensional underwater tracking algorithm that accounts for environmental effects resulting from acoustic ray bending by the ocean. A modified spherical extended Kalman filter (MSEKF), which assumes straight-line propagation, is used in conjunction with a source position correction table. This table delineates the difference between the source´s apparent and actual positions obtained by straight-line propagation and ray path bending. The MSEKF recursively estimates source position and velocity, with appropriate corrections made for the environment.