Integrated acoustics systems for ocean observatories

Abstract

Integrated acoustics systems providing navigation and communications and conducting acoustic measurements in support of science applications is, in concept, analogous to the Global Positioning System, but relies on acoustics because the ocean is opaque to electromagnetic waves and transparent t o sound. A series of nested systems is envisioned, from small-to regional-to basin-scale. A small number of acoustic sources sending coded, low power signals can service unlimited numbers of inexpensive receivers. Drifting floats with receivers can be tracked accurately while collecting ocean circulation and heat data, as well as ambient sound data about wind, rain, marine mammals, and seismic activity. The sources can double as transmiters of control data from users to remote instruments; if enabled as receivers, two-way acoustic communications links in large-scale networks can be established. Acoustic-based instrumentation that shares the acoustic bandwidth with, and depends upon, the navigation and communications capabilities completes the concept of integrated acoustic systems.