Abstract:In order to accurately estimate the GNSS velocity field in Jiangxi province and its adjacent area, we select the coordinate time series of 133 GNSS stations in the study area from the crustal movement observation network of China(CMONOC), and deeply study the influence of environmental loading changes on noise models. We calculate the nonlinear change caused by environmental loading, use the maximum likelihood criterion and Bayesian information criterion to determine the optimal noise model of each coordinate time series before and after loading correction, and estimate the velocity uncertainty. The combination of flicker noise and white noise is the main noise model of 133 GNSS stations in Jiangxi and its adjacent area. The noise characteristics of coordinate time series can be directly affected by environmental loading correction. Moreover, the velocity uncertainty of E, N and U directions decrease by 23%, 22% and 21%, respectively, after adding the environmental loading correction. The results show that environmental loading correction is helpful to accurately determine the optimal noise model of GNSS stations in Jiangxi and its adjacent area, and improve the accuracy and reliability of velocity field estimation. It is suggested to consider the influence of environmental loading when calculating GNSS velocity field.