Japan Geoscience Union Meeting 2016

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Oral

Symbol S (Solid Earth Sciences) » S-CG Complex & General

[S-CG59] Ocean Floor Geoscience

Wed. May 25, 2016 1:45 PM - 3:15 PM 301B (3F)

Convener:*Kyoko Okino(Ocean Research Institute, University of Tokyo), Keiichi Tadokoro(Research Center for Seismology, Volcanology and Earthquake and Volcano Research Center, Nagoya University), Osamu Ishizuka(Geological Survey of Japan, AIST), Tomohiro Toki(Faculty of Science, University of the Ryukyus), Narumi Takahashi(Research and Development Center for Earthquake and Tsunami, Japan Agency for Marine-Earth Science and Technology), Chair:Yojiro Yamamoto(Japan Agency for Marine-Earth Science and Technology), Mikiya Yamashita(Japan Agency for Marine-Earth Science and Technology)

1:45 PM - 2:00 PM

[SCG59-01] Uncertainty of vertical positioning of seafloor geodetic observation

*Tadashi Ishikawa1, Shun-ichi Watanabe1, Yusuke Yokota1, Toshiharu Tashiro1 (1.Hydrographic and Oceanographic Department, Japan Coast Guard)

Keywords:Seafloor geodetic observation, GPS-Acoustic combination technique

The Hydrographic and Oceanographic Department of Japan Coast Guard has been developing a system for precise seafloor geodetic positioning with the GPS-Acoustic combination technique and deploying seafloor observation sites on the landward slope of the major trenches around Japan, such as the Japan Trench and the Nankai Trough.
For the precise GPS-Acoustic seafloor positioning, we are developing analysis software, which combines a kinematic GPS result and an observed acoustic travel time to get a precise position of an array of seafloor stations. In this analysis, vertical coordinates of seafloor stations and the sound velocity are not completely independent. Therefore vertical coordinates are influenced by the error of sound velocity and in consequence their accuracy is more deteriorated than that of horizontal coordinates.
In this presentation, we present a new analysis strategy for precision improvement.