QZSS系统在中国区域增强服务性能评估与分析

日本准天顶卫星系统(QZSS)是区域性辅助与区域增强一体的导航系统,覆盖区域为日本及周边区域,包括我国部分区域,该系统采用IGSO卫星播发L1-SAIF与LEX两类增强信息,可以提供我国部分区域用户的高精度定位。本文从可用性、空间信号精度、用户动态精密单点定位几个方面对QZSS两类增强信号在中国区域的性能进行较为全面的评估,并采用QZS-1卫星实测数据进行实验,结果表明,以20°为截止高度角,中国大部分区域,尤其是东部沿海地区一天之内80%的时段可连续观测QZSS卫星;L1-SAIF差分增强信息可实现与目前WAAS相当的精度,URE约0.56 m,满足1 m左右的精密单点定位,平面精度优于1 m;与L1-SAIF相比,LEX精度更高,轨道与钟差精度可达dm级,URE约0.4 m,可实现亚m级定位,平面0.2 m,高程0.5 m。

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.