基于IGU预报轨道实时估计精密卫星钟差

REAL-TIME ESTIMATION OF PRECISE SATELLITES CLOCK BIAS BASED ON IGU PREDICTED ORBIT

针对目前实时精密单点定位中,GPS卫星实时钟差服务所存在的精度问题,提出了一种基于IGU轨道的实时钟差估计方法。该方法基于IGU轨道,采用全球参考站非差载波相位观测值,进行实时钟差估计。数值结果表明：实时估计的卫星钟差与IGS最终产品的偏差大部分小于0.3 ns,平均优于0.2 ns;采用估计所得的实时钟差进行PPP静态定位,其精度可达12 cm,同时也可得到毫米级精度的天顶对流层延迟。

Aiming at the accuracy of the GPS satellite clock bias service the real-time precise point positioning（PPP） currently,a method for real-time estimating the satellite clock bias based on the basis of IGU（IGS Ultra-rapid） predicted orbits is put forward.In this method the un-differenced carrier phase observations of global reference stations is used to estimate the real-time clock bias.Numerical calculation results show that most of deviations between the estimated satellite clock bias and the IGS final product are less than 0.3 ns,and the average accuracy is better than 0.2 ns;with the real-time estimated satellite clock bias,the static accuracy of PPP can achieve 1-2 cm,but also the accuracy of zenith tropospheric delay（ZTD）,can reach to millimeter level.