摘要
根据GALILEO系统的完备性指标概念,采用基于轨道误差和卫星钟差协方差矩阵计算完备性指标的方法,利用GPS星历数据计算和分析了空间信号误差(SISE)和完备性指标(SISA)的变化和分布情况。结果表明,GPS卫星各分量中误差相差较大,对于不同的卫星应分别计算其完备性指标;不同GPS卫星的SISE随时间的变化幅度不同,呈明显的随机性;在中国区域内,SISA的变化具有一定的规律性,在低纬高经度地区SISA具有较小的数值,在同一高纬地区SISA的数值相近;针对GPS系统的SISA计算结果,GALILEO系统需大幅提高轨道和钟差预报精度才能满足生命安全服务要求。
The variation and distribution of signal-in-space error and signal-in-space error accuracy were calculated and analyzed according to the covariance of satellite orbit error and clock error and the integrity concept of GALILEO system. The data used were from GPS navigation file and IGS precise orbit. The result revealed that the orbit and clock RMSs of different satellites varied greatly. So integrity index was calculated independently. The value of SISE varied with time randomly for different satellite and the spatial variation of SISA had certain law, which meant that SISE values were small in the lower latitude region and similar SISE values were similar for the same high latitude region. According to the calculation results, the satellite orbit and clock of GALILEO forecast accuracy should be improved greatly to satisfy service of safety.
出处
《测绘科学技术学报》
北大核心
2007年第5期340-342,345,共4页
Journal of Geomatics Science and Technology
基金
山东省基础地理信息与数字化技术重点实验室开放基金资助项目(SD060812)
国家自然科学基金资助项目(40504003)
