IAG-IASPEI 2017

講演情報

Oral

IAG Symposia » G07. Global Geodetic Observing System (GGOS) and Earth monitoring services

[G07-1] GGOS activities and focus on gravity

2017年8月3日(木) 13:30 〜 15:00 Room 502 (Kobe International Conference Center 5F, Room 502)

Chairs: Richard Gross (Jet Propulsion Laboratory, California Institute of Technology) , Toshimichi Otsubo (Hitotsubashi University)

14:15 〜 14:30

[G07-1-04] Space Geodetic Activities and GGOS Working Group in Japan

Toshimichi Otsubo1, Basara Miyahara2, Ryoji Kawabata2, Yuichi Aoyama3, Yuichi Fukuda4, Yusuke Yokota5, Hiromi Yamao2, Shigaru Matsuzaka6 (1.Hitotsubashi University, Kunitachi, Japan, 2.Geospatial Information Authority of Japan, Tsukuba, Japan, 3.National Institute of Polar Research, Tachikawa, Japan, 4.Kyoto University, Kyoto, Japan, 5.Japan Coast Guard, Tokyo, Japan, 6.(retired) Geospatial Information Authority of Japan, Tsukuba, Japan)

Japan has been actively involved in space geodetic observations, technical developments and data analyses since 1970s. Eminent long-term examples are Shimosato Hydrographic Observatory for SLR (Satellite Laser Ranging), GSI (Geospatial Information Authority of Japan) Tsukuba Station and NIPR (National Institute of Polar Research) Syowa Station for VLBI (Very Long Baseline Interferometry), and NICT (National Institute of Information and Communications Technology) being one of the VLBI Technical Development Centers. More institutes and individuals have a number of achievements.

Japanese geodetic activities had leaned a little to monitoring local and regional deformation. At the early stage of IAG GGOS (Global Geodetic Observing System), Japan did not present much involvement, but the “GGOS Working Group" was formed in 2013. Helped by a number of institutes and organizations, the Geodetic Site List was assembled in 2014 where 10 geodetic sites in Japan and one geodetic site in Antarctica were included. Each site has at least one VLBI or SLR station collocated with a GNSS station, and some of them has a DORIS antenna and a gravimeter. The list was submitted to the GGOS bureau and all sites were approved as a GGOS site. It should be noted that 5 different institutes own and operate these sites. Each of them has its own backgrounds and missions but all of them have worked in collaboration.

Due to seismic deformation, especially the 2011 Tohoku Earthquake, the motion of the geodetic sites in Japan cannot be properly expressed by the conventional piecewise linear function. However, the use of post-seismic deformation models newly introduced in ITRF2014 is expected to ease the problem, and the Japanese stations can contribute to global-scale geodetic products.

The GGOS WG of Japan strives to improve the quality and productivity of our geodetic stations, to encourage the collaboration beyond each technique, and to make/help strategic projects for the future.