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.