Abstract:In order to simplify the calculation of GNSS precipitable water vapor(PWV) and improve its real-time calculating efficiency, we analyze the linear relationship between GNSS-PWV and tropospheric delay(ZTD), surface temperature(T) and atmospheric pressure(P) using the GNSS data from 7stations in the Yangtze River Delta during 2017-2018. The general PWV direct transformation regional model for the Yangtze River Delta is established using the linear fitting. The experimental results show that PWV has a good correlation with ZTD, P and T, and their correlation coefficients are 0.99, -0.74 and 0.73 respectively. The RMS of the yearly single-factor PWV model based on ZTD is 3.07 mm, the RMS of the yearly double-factor PWV model based on ZTD and T is 2.35 mm, the RMS of the yearly double-factor PWV model based on ZTD and P is 1.18 mm and the RMS of the yearly multi-factor PWV model based on ZTD, T and P is 0.47 mm. The average RMS of the seasonal multi-factor PWV models based on ZTD, T and P is 0.28 mm, which is slightly better than that of the yearly multi-factor PWV model.