Evaluation of QZSS System Augmentation Service Performance in China Region

The Japanese QZSS(Quasi-Zenith Satellite System)is a satellite navigation system combing regional assistance with enhancement and covering Japan and surrounding area including partial area of China. The system broadcasts two enhancement signals L1-SAIF and LEX through IGSO and can provide high precision positioning in China region. From the aspects of availability, space signal accuracy and user kinematic PPP(precise point position), this paper comprehensivelyevaluate the performance of QZSS two enhance signals in region of China. With QZS-1 measured data, we executed experiments; the results show that, with 20°cut-off elevation, most areas of China, especially the eastern coastal area can observe the QZSS satellite about 80% of the day; a wide area differential message achieves considerable accuracy when compared with WAAS, as the URE(User Range Error) is about 0.56m and satisfies PPP needs with an accuracy of 1m. The horizontal accuracy is better than 1m; when compared with L1-SAIF, the accuracy of LEX was higher, the accuracy of orbit and clock was decimeter-class. The URE is about 0.4m, achieving sub-meter class positioning with an accuracy of 0.2 m in the horizontal and 0.5 m in the height dimensions.