Impact of speed of sound uncertainties on model-based positioning

In this paper, the impact of speed of sound uncertainties on ray-tracing based acoustic underwater positioning is investigated. Therefore, the model-based positioning approach recently proposed by the authors in [1] is simplified in sound ranging. Based on the new method the impact of different sound speed values in the distance estimate is studied. Furthermore, we analyze the effect of recording of a few measured values of the sound speed profile (SSP) on the ranging accuracy using the model-based approach. Altogether, it can be concluded that the resolution of the SSP has a significant influence on the accuracy of the distance estimation. A challenging effect is the nonlinearity in the SSP, which is addressed and discussed. Taking into account the nonlinearity in the distance estimate, investigations for a deep-water environment show promising results.