Establishing a high-precision real-time regional tropospheric model and its application in precise point positioning
The accuracy and stability of the current real-time tropospheric delay models are subject to further improvement due to the limitations of the tropospheric delay modeling method and the accuracy and temporal resolution of the observation data required for modeling.In this paper,a real-time high-precision ZTD(Zenith Troposphere Delay)grid model with 0.25° x0.25° spatial resolution is constructed for the Gansu region using the ZTD estimated from 184 ground-based GNSS(Global Navigation Satellite System)stations in and around Gansu.To address the problems of low accuracy of the traditional elevation normalization model and horizontal interpolation model,this paper proposes the use of Gaussian exponential function model and BP neural network model for ZTD elevation normalization and horizontal interpolation respectively.In order to verify the accuracy of the new ZTD grid model,data from eight CMONOC stations in Gansu Province that were not involved in the modelling of the land state network was selected for the experiment.The statistical results show that the RMS of the deviation between the ZTD grid model and the post-processing GNSS-ZTD is better than 1.52 cm.In addition,the ZTD real-time grid model is used to constrain PPP(Precise Point Positioning)processing.After ZTD constraints are applied to the PPP floating point solution,the U direction accuracy is improved by 22.9％,and the U direction convergence time is shortened by 26.4％.
万方数据
维普
