Results from recent sea trials of the Underwater Digital Acoustic Telemetry system

The Underwater Digital Acoustic Telemetry (UDAT) system is a set of underwater acoustic telemetry modems developed by the Test and Evaluation Department at the Naval Undersea Warfare Center Division, Newport. The modems were designed to provide robust underwater acoustic communication at throughput data rates of approximately 900 and 1800 bits per second. Since February 1996 the modems have been used in seven exercises in four diverse deep water and shallow water environment. The results from the tests are very encouraging. Continuous, low error transmission has been achieved over many minutes (/spl sim/20 min.). Detection ranges for the system have exceeded 4 km in shallow water and 8 km in deep water. In January 1997, the acoustic modems were used for continuous, full duplex communications. This paper reviews the design of the UDAT system, discusses the results from the field tests, and presents the current status of the modems.