Acoustic Modem Performance in a Three-Dimensional Harbor Environment

Abstract

Understanding sound behavior in nearshore constrained environments such as ports and harbors renders unique challenges. Improving sound models in these channels offers many advantages, such as increasing the effectiveness of model-based design of underwater acoustic systems that enable harbor security. Our ongoing efforts focus on acoustically characterizing these complicated nearshore channels, analyzing acoustic communication system performance, and refining a 3D beam tracing propagation model for simulating modem transmission. Measurements collected in an industrialized estuarine harbor demonstrate sound propagation effects not only from the boundary features (i.e. bathymetry, surrounding human-made obstacles) but also from the environment as a function of varying bottom type and coastal water column SSP effects. Field observations are compared with 3D sound model simulations to identify feature and boundary reflection properties that contribute or dominate measured echo structure. A verified comprehensive modeling ability for these dynamic, and acoustically distinct, constrained environments is ideal for executing successful underwater operations such as utilizing acoustic modem networks.