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Volume 38 (1992)
- Issue 4 Pages 315-
- Issue 3 Pages 211-
- Issue 2 Pages 89-
- Issue 1 Pages 1-
Volume 38, Issue 4
Displaying 1-4 of 4 articles from this issue
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Ichiro NAKAGAWA1992 Volume 38 Issue 4 Pages 315-316
Published: December 25, 1992
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSDownload PDF (249K) -
Yukio HAGIWARA1992 Volume 38 Issue 4 Pages 317-328
Published: December 25, 1992
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSGPS has a significant impact on various fields of geodetic sciences. The conventional geoid-based concept of "gravity anomaly" should be changed to a new definition in association with the ellipsoidal height system. Terrestrial geodetic methods such as triangulation and long-range leveling surveys will possibly be replaced by GPS methods. Instead of tide-gauge observations, GPS geodesy should play an important role in monitoring secular sea level rise resulting from global warming induced by atmospheric carbon-dioxide content increase. Under such circumstances, the number of paper contribution to the Geodetic Society of Japan has significantly increased concurrently with the introduction of GPS technique.View full abstractDownload PDF (4018K) -
Teruyuki KATO1992 Volume 38 Issue 4 Pages 329-348
Published: December 25, 1992
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSRecent global campaigns, such as GIG'91, demonstrated that GPS is attaining a similar accuracy as VLBI or SLR in determining station coordinates and earth rotation parameters. Given this development together with economical merits, GPS will soon be used as a powerful tool for studying global geodesy and geodynamics. Examples are; monitoring sea level rise, establishing and maintaining the conventional terrestrial frame, monitoring global plate motions, studying dynamics in fluctuations of earth's rotation etc. International GPS Geodynamics Service (IGS), which is the voluntary organization under JAG, will play a key role for these studies. When this organization is operational and its products are readily available for local and regional users, geodetic and geophysical studies of regional scales with GPS will also rapidly advance. As well as other regional campaigns, GPS JAPAN is one of such efforts that has been coordinated in Japan with the aid from surrounding countries. GPS JAPAN targets to facilitate studies of the regional scale problems such as finer tectonics at plate boundaries, local crustal deformation monitoring related to seismic and volcanic activities and so on, by densifying the regional networks around the Japanese core sites and thereby materializing the regional orbit improvements.View full abstractDownload PDF (2169K) -
Hiromichi TSUJI, Masaaki MURATA1992 Volume 38 Issue 4 Pages 349-366
Published: December 25, 1992
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSIn this review on Global Positioning System (GPS) satellites' orbits, basic concepts of orbit determination are introduced first. Next, a history of orbit determination activities from 1985 to 1992 is reviewed with the emphasis on strategies which enable accuracy improvements. The initial accuracy of GPS ephemeris was around 10 m in orbits or 0.1 ppm in baseline components. The current orbit accuracy reaches some tens of cm, producing baseline accuracy of 0.01 ppm. Twenty times accuracy improvement within seven years is astonishing. The evolution is still going on and leads to an international effort to establish a GPS orbit information service. Given the global tracking network and precise orbit service through international cooperation, GPS will be an indispensable utility of geodesy and geodynamics with mm accuracy in the near future.View full abstractDownload PDF (2270K)
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