Development of Underwater Acoustic Modems and Networks

RECENT DEVELOPMENTS in underwater acoustic communication enable real-time contact with underwater sensors, vehicles, and other instruments, offering novel ocean observational capabilities that may change future oceanographic operations. This article summarizes the current state of the art in underwater acoustic communication and telemetry equipment. Acoustic transmission is an attractive option for underwater communication only because radio frequency (RF) and optical energy are severely attenuated under water, whereas acoustic energy propagates well. Information encoded and transmitted on a modulated acoustic waveform can be received and decoded by distant underwater receivers.