Technology of Precise Orbit Determination

Since 1971, most domestic orbit determination systems have been developed by Fujitsu and its technology is highly evaluated by people involved in the field. In the mid-1990s, with the increased precision and sophistication of satellite Earth observations there was a need for greater accuracy in determining orbits that could not be provided by conventional systems. Thus, the Japan Aerospace Exploration Agency (JAXA; formerly known as the National Space Development Agency of Japan) has planned the development of a Global and high accUracy Trajectory determination System (GUTS), which uses GPS and satellite laser ranging (SLR) technology. Fujitsu developed the core technology for this and operated the system. Furthermore, Fujitsu has been engaged in the operation of GUTS and is committed to maintaining and improving the precision of orbit determination technology through continuous improvement of this system. This paper introduces the overview of the GUTS, core technologies related to orbit determination developed by Fujitsu and the current situation with regards to derived precision of orbit determination. It also describes the overview of a precise positioning experiment system based on our experience of using the core technology of GUTS.