Implementation of the QZSS L1-SAIF Message Generator

Takeyasu Sakai, Sonosuke Fukushima, Noboru Takeichi, and Ken Ito

Abstract:	QZSS (quasi-zenith satellite system) is a Japanese satellite navigation program with a regional service coverage planned to be launched by 2010. The orbits for QZS (quasi-zenith satellite) are 24-hour elliptic orbit inclined 45 degrees in order to broadcast radiosignals from high elevation angle into urban canyons. QZSS will offer both supplement and augmentation signals in order to offer the maximum benefit to users. QZSS will broadcast GPS augmentation messages on the GPS L1 frequency. For this purpose L1-SAIF (submeterclass augmentation with integrity function) signal has been developed based on SBAS standard because both of them offer similar function to the almost same service area. The target of user position accuracy with augmentation was set to 1 meter RMS. QZSS will also provide the integrity function necessary for safety of mobile users. L1-SAIF augmentation messages are designed to be upper compatible with SBAS messages; The extended messages are also designed to enhance the performance of augmentation system. L1-SAIF augmentation messages are generated at L1- SAIF Master Station (L1SMS) and broadcast to the experimental area via QZSS MCS and QZS. The ENRI, Electronic Navigation Research Institute, has been developing L1SMS as a part of the national QZSS program. In this paper the authors describe the configuration of L1SMS and its subsystems. The most important subsystem, L1-SAIF Message Generator (L1SMG), is explained in detail based on the WADGPS technique. Also, initial results of realtime operation test demonstrate that the target accuracy of 1 meter RMS is likely achievable.
Published in:	Proceedings of the 2008 National Technical Meeting of The Institute of Navigation January 28 - 30, 2008 The Catamaran Resort Hotel San Diego, CA
Pages:	464 - 476
Cite this article:	Sakai, Takeyasu, Fukushima, Sonosuke, Takeichi, Noboru, Ito, Ken, "Implementation of the QZSS L1-SAIF Message Generator," Proceedings of the 2008 National Technical Meeting of The Institute of Navigation, San Diego, CA, January 2008, pp. 464-476.
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