Abstract:The retrieval of tropospheric and ionospheric parameters from global and regional Global Navigation Satellite System (GNSS) reference station networks has the benefits of low cost,high precision and real-time.The GNSS space environmental monitoring platform of Xsensing proposed by Nanjing University of Information Science and Technology is introduced in this paper.Firstly,the accuracy of tropospheric parameter inversion under different meteorological conditions is evaluated with the tropospheric products provided by the international GNSS service as a reference.Then,the ambiguity-fixed Precise Point Positioning (PPP) method is used to realize high-precision ionospheric parameter inversion.The experimental results show that the mean bias of the tropospheric delay errors is 0.05 mm,and the corresponding standard deviation is 5.6 mm.The results can reflect the trend of water vapor changes with high accuracy under stable or severe weather conditions.The accuracy of ionospheric inversion is evaluated based on a short baseline test.The mean bias of ionospheric delay errors from the ambiguity-float PPP is -0.09 TECU,and the accuracy is 0.38 TECU.The ambiguity fixed PPP method can improve the accuracy by 84.2%.Besides,comparable accuracy can be achieved using the static and simulated kinematic PPP.The results verify the initial accuracy of the Xsensing platform and pave the way for improving the spatial and temporal resolution of the space environment monitoring using airborne and shipborne platforms.