Research Activities : Space Geodesy

Space Geodesy stands for space based precise measurement techniques for Geodesy, which include Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), and Global Positioning System (GPS). Radio Astronomy Applications Section is studying Geodynamics by means of these Space Geodetic techniques, especially VLBI.

Key Stone Project (KSP)

KSP is the project to monitor regional crustal deformations in the Tokyo metropolitan area by using space geodetic techniques. The KSP has been started in 1993 by CRL.

Western Pacific VLBI Network (1989-1994)

Minamitorishima (Marcus Is.)

Western Pacific VLBI Network (WPVN) was deployed by CRL in 1989 to monitor the motion of two oceanic plates (Pacific and Philippine Sea plates) around Japan. The WPVN consists of three Japanese stations and one Chinese station on the four different plates, i.e., Kashima (North American plate), Minamitorisima (Pacific plate), Minamidaitojima (Philippine Sea plate), and Shanghai (Eurasian plate), respectively. We have detected the motion of Minamitorishima close to the NUVEL-1 plate motion model.

Details of the Western Pacific VLBI Network experiments and related research topics and developments were presented in the special issue of the Journal of the Communications Research Laboratory published in 1995 (Journal of the Communications Research Laboratory, Vol. 42, No. 1, 1995).

Collaborations with Related Research Organizations

NASA / Dynamics of Solid Earth Program

CRL has participated more than 150 international VLBI experiments under the Crustal Dynamics Project of NASA using both 26m antenna station since 1984 and 34m antenna station since 1989. At present, Geodetic Survey Institute is in charge of 26m antenna station at Kashima and is participating NASA's Dynamics of Solid Earth Program (expanded follow-on program of Crustal Dynamics Project).

Precise Earth Rotation Measurements

Kashima 34m antenna station has been participating IRIS-P (International Radio Interferometric Servey - Pacific experiments coordinated by IERS) and NAVEX (international campaign coordinated by US Naval Observatory) for precise Earth rotation measurements.

Domestic Cooperations

Communications Research Laboratory is cooperating with Geographical Survey Institute, National Astronomical Observatory, Institute for Space and Aeronautical Sciences, National Institute for Polar Research and Kagoshima University for domestic VLBI experiments and technical developments for the VLBI research.

Research Publications

Please send any questions and comments to us.

Return to Radio Astronomy Applications Section

Last Update: July 3, 1998