Analysis of underwater acoustic propagation in a harbour environment and its effect on communication

Acoustic underwater communication is an enabler for the use of autonomous underwater vehicles (AUVs). AUVs can operate in acoustically challenging environments, e.g., near offshore platforms and in harbours. To realize robust underwater communication in such environments, the propagation conditions need to be properly understood. In this paper, the performance of underwater acoustic communication in shallow water harbour environments is investigated. To perform our investigation, channel soundings (i.e., empirical channel impulse responses) captured in the Port of East-Vlissingen (The Netherlands) are employed. In particular, it is investigated how the increase of acoustic reverberation caused by reflections from physical structures in a harbour (e.g., quay walls, jetties, piers) affects the underwater acoustic communication performance. The empirical reverberation obtained from the channel soundings is compared with the modelled two-dimensional equivalent in order to make a distinction between bottom-surface paths and reflections from physical structures in the harbour. The collected channel soundings and their analysis are necessary for the development of novel modulation methods and provide useful input for an improved understanding of the acoustic propagation conditions in harbour environments. The findings in this paper can be used by future tools for autonomous underwater operations.