User-Side Long-Baseline Undifferenced Network RTK Positioning Under Geomagnetic Storm Conditions Using a Power...

Area of Science:

• Geodesy and Geomatics
• Space Weather Effects on GNSS

Background:

• Long-baseline undifferenced network real-time kinematic (URTK) positioning accuracy degrades under extreme space weather.
• Geomagnetic storms cause severe ionospheric delays, impacting regional correction model availability.

Purpose of the Study:

• To propose a user-side atmospheric delay estimation strategy for URTK to improve positioning performance during geomagnetic storms.
• To enhance positioning availability and accuracy in challenging space weather environments.

Main Methods:

• Implemented an ambiguity-resolution model to fix carrier-phase integer ambiguities for long-baseline reference stations.
• Recovered station-specific undifferenced integer ambiguities and computed correction terms.
• Estimated residual atmospheric parameters on the user side after applying regional corrections.

Main Results:

• The proposed strategy significantly improves user-station positioning accuracy during geomagnetic storms.
• Under strong storms, accuracy improved by 63.7% (East), 60.7% (North), and 64.4% (Up).
• Under moderate storms, accuracy improved by 16.7% (East), 10.0% (North), and 11.1% (Up).

Conclusions:

• The user-side atmospheric parameter estimation effectively enhances positioning availability during geomagnetic storms.
• The server-side system remains operational without significant impact during geomagnetic storms.
• The proposed method offers a robust solution for maintaining high-precision GNSS positioning under adverse space weather.