A compact underwater acoustic modem

A major focus of the Acoustic Telemetry Group at Woods Hole Oceanographic Institution has been the development of adaptive algorithms for use in underwater acoustic communications, particularly in shallow water applications and in acoustic local area networks. As the current generation of commercial telemetry devices do not meet the computational requirements of such algorithms, a new compact signal-processing module has been developed. The key feature for this unit is that it is able to provide data processing rates of at least 80 Mflops (million floating-point operations per second) while being sufficiently compact for hand deployment and having low quiescent power consumption for long-term deployment. This paper presents details of the modem hardware and software architecture together with preliminary results from the first deployment using the new system.