基于IGS跟踪站的高频GPS卫星时钟改正确定

利用IGS跟踪站的GPS观测数据,通过数据预处理,先求得对流层延迟参数,再解算高频(30 s)GPS卫星时钟改正,并与CODE(center for orbit determination in Europe)给出的30 s一笔的高频时钟数据进行比较,两者平均差异为0.003 234 ns,平均标准差为0.607 6 ns。通过比较,发现在20世纪90年代发射的BlockIIA卫星携带的Cs钟不如Rb钟稳定和可靠,Block IIR卫星携带的时钟优于Block IIA卫星钟。

Determination of High-Rate Clock Corrections for GPS Satellites from Observations of IGS Stations

GPS observation data from International GNSS Service(IGS) stations are used to calculate the high-rate GPS satellite clock corrections at the interval of 30.After GPS data preprocessing,the tropospheric parameters are computed in order to get the high-rate clock corrections.The high-rate results solved are compared with the high-rate clock data in 30 from CODE.The mean difference is 0.003 234 ns,the mean standard deviation is 0.607 6 ns,which indicate that the results can get the high precision at the level of 0.7 ns.It is found that Cs clocks onboard Block IIA satellites launched in 1990s have no more stabilization and reliability than Rb clocks.Atomic clocks onboard Block IIR satellites outgo those onboard Block IIA satellites.