Estimation of the Precipitable Water Vapor from ground-based GPS with GAMIT/GLOBK

Information about the amount and spatial structure of atmospheric water vapor is essential in understanding weather forecasting and climate change. This paper mainly discuss the principles and methods to deduce the atmospheric Precipitable Water Vapor (PWV) from ground-based GPS observations by using a high accuracy GPS processing software package- GAMIT/GLOBK version 10.34. A GPS-network including 6 ground-based GPS receiving stations in China was employed to study the estimations of PWV, which were compared with the corresponding PWV data measured by the radiosondes. The RMSE of the GPS-PWV derived by our calculations is 4.3 mm. The results of the present study show that there is a good coherence between the GPS-PWV and the Radiosonde-PWV, indicating that the GPS algorithm for deriving PWV is effective.