hide
Free keywords:
-
Abstract:
As wide-area atmosphere correction models often struggle to attain high-precision and uniformity, especially in regions experiencing rapid atmospheric changes, they are usually as constraints to the user-end atmospheric parameters. The proper constraint is crucial for rapid or instantaneous convergence in Precise Point Positioning with Ambiguity Resolution (PPP-AR). However, the empirical uncertainty information commonly adopted cannot accurately represent the actual quality of a real-time established model. To address this problem, we propose an approach to determine atmospheric uncertainty information using the residuals of the atmosphere delays fitting to a polynomial model. Two sets of 2°×2° grids with a 15-minute update rate are generated based on the fitting residuals of tropospheric and satellite-wise slant ionospheric delays derived using PPP-AR at all reference stations. The proposed approach is verified using 166 EUREF Permanent Network stations with a 150 km station-spacing and validated using 113 additional stations. The utilization of wide-area grid uncertainty information leads to an average convergence time that reduces to 1.5 min, i.e., improved by up to 36% compared to the legacy empirical constraints. Additionally, an improvement of 9% in the fixing rate compared to the empirical constraint solutions is observed. In conclusion, the provision of atmosphere uncertainty information accurately characterizes the performance of the fitting model in all coverage areas, resulting in rapid positioning performance with lower computational resources.
