Detection of precipitable water vapor during summer rainfall by Nanjing GPS network

According to the ground-based principles of GPS meteorology, utilizing on the observation data of Nanjing regional GPS network, introducing the observation data of three IGS base stations to construct very long baselines, and combining with the atmospheric parameters by surface observation, the GPS absolute precipitable water vapor (PWV) and relative PWV were estimated. Compared with SONDE PWV and the actual surface rainfall, results show that there has a good relativity between GPS PWV and SONDE PWV; according to SONDE PWV, whether the average difference or correlation coefficient, GPS absolute PWV is better than relative PWV; The variation of GPS PWV value can be an intuitive response to changes in the actual surface rainfall, and Rainfall usually occurs in 4-6 hours after the value of GPS-PWV had a rapid increase; and with the value of GPS PWV significantly rise or drop, it shows the beginning or end of the rainfall. In addition, it's useful for studying on regional changes in atmospheric water vapor with Estimating PWV by regional GPS network, and can improve the accuracy of meso-, micro-scale weather forecast.