Computer Simulation of Remote Synchronization System of Onboard Crystal Oscillators for Quasi-Zenith Satellites
- Paper number
IAC-05-D1.4.02
- Author
Dr. Toshiaki Iwata, National Institute of Advanced Industrial Science and Technology, Japan
- Coauthor
Mr. Yasuhiro Fukuyama, National Institute of Advanced Industrial Science and Technology, Japan
- Coauthor
Mr. Ken Hagimoto, National Institute of Advanced Industrial Science and Technology, Japan
- Coauthor
Dr. Takeshi Ikegami, National Institute of Advanced Industrial Science and Technology, Japan
- Coauthor
Mr. Michito Imae, National Institute of Advanced Industrial Science and Technology, Japan
- Coauthor
Dr. Akira Iwasaki, University of Tokyo, Japan
- Coauthor
Mr. Hiroshi Murakami, National Institute of Advanced Industrial Science and Technology, Japan
- Coauthor
Mr. Ken Nakajima, Mistubishi Space Software Co. Ltd., Japan
- Coauthor
Dr. Tomonari Suzuyama, National Institute of Advanced Industrial Science and Technology, Japan
- Coauthor
Mr. Naoto Takasaki, University of Tokyo, Japan
- Year
2005
- Abstract
Japan’s Quasi-Zenith Satellite System (QZSS), which will be launched in 2008, is expected to be effective for overcoming various obstacles, including mountains and urban canyons, and providing stable satellite mobile communication, broadcasting, and positioning services. This system will be loaded with such atomic clocks as cesium, rubidium, and hydrogen maser. However, the atomic clocks are massive and expensive, and have a short lifetime. Therefore, we have proposed the employment of a remote synchronization system of onboard crystal oscillators (RESSOX) from a ground station, in lieu of the atomic clocks. The RESSOX uplinks the time signal that compensates the delay between the satellite and the ground station in order to synchronize the onboard crystal oscillators exactly with the atomic clock of the ground station. However, many issues remain to be resolved prior to the realization of the RESSOX, including the error origin of the time signal, such as ionosphere delay, troposphere delay and distance delay of microwave; orbit estimation; relativity effects; coordinate transformation and control algorithms of the on-board crystal oscillators; and ground station timing adjustment. These issues are discussed individually, and computer simulation that takes these issues into consideration is conducted. The simulation cases are as follows: (1) no errors in orbit estimation, clock synchronization, and other factors, (2) orbit estimation has errors, and (3) clock synchronization has errors.
- Abstract document
- Manuscript document
IAC-05-D1.4.02.pdf (🔒 authorized access only).
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