Influence Analysis of IGU Predicted Products on the Tropospheric Delay of a Single Receiver

Based on the precise point positioning, the impact of IGU predicted orbit and clock error on the accuracy of real-time obtaining zenith tropospheric delay (ZTD) of a single receiver was compared and analyzed. Theoretic study and experiment analysis shown that the IGU predicted orbit can satisfy the real-time ZTD accuracy. But, as to the IGU predicted clock errors, its real-time obtained ZTD accuracy (~ 2cm) can't meet the need for the accuracy of GPS remote sensing of water vapor. Therefore, we need a new method to real-time estimate the precise predicted satellite clock errors.