Abstract:Based on the GPT3 model, GNSS observation data and meteorological data of multiple radiosonde stations in Yangtze River Delta, we evaluate the precision, reliability and real-time performance of PWV calculated by GPT3 model, 2 surface meteorological data methods and GNSS, compared with the radiosonde PWV as the true value. The results show that the GPT3 model can be used to obtain real-time PWV with low precision. GNSS-PWV has the highest precision, but it needs measured meteorological parameters, which limits its widespread application. The 2 surface meteorological data methods have the higher precision, but they need surface dew point temperature data.