Regiomontan: A Regional High Precision Ionosphere Delay Model and Its Application in Precise Point Positioning

Area of Science:

• Geodesy and Satellite Navigation
• Atmospheric Physics

Background:

• Ionospheric delays in Global Navigation Satellite System (GNSS) signals can reach several meters, necessitating precise corrections.
• Dual-frequency GNSS receivers can mitigate these effects, but single-frequency users require external ionospheric information.

Purpose of the Study:

• To evaluate the performance and accuracy of the Regiomontan regional ionospheric delay model.
• To assess the model's utility in Precise Point Positioning (PPP) applications for users in Austria.

Main Methods:

• Utilized dual-frequency phase observations from a regional GNSS network (EPOSA) to develop the Regiomontan model.
• Applied the Regiomontan model within an in-house PPP software (raPPPid) using an uncombined model with ionospheric constraints.
• Conducted tests analyzing coordinate convergence and comparing estimated versus modeled ionospheric delays.

Main Results:

• Regiomontan provides high-accuracy ionospheric delay corrections with a latency of only a few hours.
• The model covers a specific geographical region within Austria and is available in the IONEX format.
• Performance tests demonstrated Regiomontan's accuracy comparable to IGS final TEC maps but with significantly reduced latency.

Conclusions:

• Regiomontan offers a valuable, low-latency solution for ionospheric error mitigation in GNSS positioning.
• The model's accuracy and reduced latency make it suitable for real-time or near-real-time applications, including Precise Point Positioning.