Study on land-to-underwater communication

JAMSTEC is conducting research and development of communication systems between underwater and land in cooperation with research institutes and manufactures. For communication between underwater and sea surface, researches of high speed acoustic communication, underwater laser communication, and radio wave communication are performed. A part of these researches including physical research of propagation is still basic research. We achieved an 80 kbps data transmission at distance of 510 m with acoustic communication, and an underwater laser communication with 10 MHz band width at distance of 20 m. For land and sea-surface communication, antennas, tracking systems, and small transceivers for sea-surface platforms are developed, prepared and tested using geostationary satellites; WINDS (Wideband Internetworking Engineering Test and Demonstration Satellite) and ETS-VIII (Engineering Test Satellite VIII). A sea trial for remote controlling of an autonomous underwater vehicle (AUV) was succeeded using the ETS-VIII. An underwater high-vision image with 32 Mbps of data rate was transmitted from the AUV when dived. These research and development results would be used to develop a multi-AUV system for research of ocean-trench earthquakes, exploration of underwater mineral resources, and so on.