HR: 1340h
AN: G13B-1232    [Abstracts]
TI: AUV-aided Seafloor Geodetic Observation System
AU: * Mochizuki, M
EM: moma@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153- 8505, Japan
AU: Asada, A
EM: asada@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153- 8505, Japan
AU: Ura, T
EM: ura@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153- 8505, Japan
AU: Fujita, M
EM: masayuki-fujita@kaiho.mlit.go.jp
AF: Hydrographic and Oceanographic Department, Japan Coast Guard, 5-3-1, Tsukiji, Chuo- ku, Tokyo, 104-0045, Japan
AU: Colombo, O L
EM: ocolombo@bowie.gsfc.nasa.gov
AF: G.E.S.T./NASA Goddard Space Flight Center, Code 698, Greenbelt, MD 20771, United States
AU: Sato, M
EM: mariko-sato@kaiho.mlit.go.jp
AF: Hydrographic and Oceanographic Department, Japan Coast Guard, 5-3-1, Tsukiji, Chuo- ku, Tokyo, 104-0045, Japan
AU: Matsumoto, Y
EM: yoshihiro-matsumoto@kaiho.mlit.go.jp
AF: Hydrographic and Oceanographic Department, Japan Coast Guard, 5-3-1, Tsukiji, Chuo- ku, Tokyo, 104-0045, Japan
AU: Tanaka, T
EM: teruki@seanet.co.jp
AF: SEA Co., Ltd., IU Building 4F, 2-23 Shiohama, Ichikawa, Chiba, 272-0127, Japan
AU: Zheng, H
EM: hzheng@seanet.co.jp
AF: SEA Co., Ltd., IU Building 4F, 2-23 Shiohama, Ichikawa, Chiba, 272-0127, Japan
AU: Nagahashi, K
EM: nagahak@mes.co.jp
AF: Underwater Engineering Department, Mitsui Engineering & Shipbuilding Co., Ltd., 3-1-1 Tama, Tamano, Okayama, 706-8651, Japan
AB: We launched a project supported by the Japan Society for the Science Promotion as the Grants in Aid for Scientific Research. In this project, we are aiming at developing new-generation seafloor geodetic observation system that conquers difficulties inherent with the current system. Central idea of this project is to utilize techniques of underwater robot (Autonomous Underwater Vehicle) and seafloor platform to make measurements in place of using the research vessels. Combination of underwater robot and seafloor platform make it possible to conduct the observation with selecting favorable condition of sea and GPS satellite distributions, to make much more frequent observations and to enable flexible planning of observation in response to sudden geodetic events. Trial model of the on-board and the seafloor units were finished. Space-saving design for the on-board unit, which controls both acoustic ranging system and GPS, was one of big issues to be overcome. We reviewed the current system configuration and made it simple. It was miniaturized, and then it was put into two cylinders. The cylinder No.1 contains the PHINS (IXSEA), an inertial navigation system based on fiber optic gyroscope technology. Another one, the cylinder No.2, contains the SF-2050M (NAVCOM Technology) GPS receiver and the acoustic ranging units. The original chassis of the SF-2050M was removed to minimize the volume of the unit and then only the electrical boards of the GPS receiver was installed into the cylinder No.2. There is no commercialized GPS antenna that can receive both L1 and L2 signals and has pressure capability of 2,000 m depth in the sea. Then we developed the pressure housing for the GPS antenna. The small size antenna corresponding to the L1 and L2 signals was installed in it. The transducer, for underwater acoustic ranging, employed on both the on-board and the seafloor units has been newly developed by Dr. Tom Ensign, Engineering acoustic Inc.. This transducer has a spherical ceramic oscillator so that it has an omni directional feature in acoustic phase response. We have performed evaluation tests for the new system. Two of them were done with AUVs in the Sagami Bay. The AUV that we utilized was one named �gr2D4�h. The r2D4 is an intelligent AUV developed by Prof. Tamaki Ura, the Underwater Technology Research Center, IIS. The others have been conducted with the mock-up of AUV. The on-board unit was installed on the mock-up, and the mock-up was towed by small boat during acoustic ranging. We will report the overview of the AUV-aided geodetic observation system and its performance, based on the several performance evaluation tests that were already done and will be done.
DE: 1294 Instruments and techniques
DE: 3050 Ocean observatories and experiments
DE: 3080 Submergence instruments: ROV, AUV, submersibles
DE: 3094 Instruments and techniques
SC: Geodesy [G]
MN: 2007 Fall Meeting