Enhancing BeiDou/GNSS integrity with minmax optimization.

Area of Science:

• Satellite Navigation Systems
• Navigation Integrity Monitoring
• Aerospace Engineering

Background:

• Integrity is critical for navigation system availability, impacting transportation, security, and surveillance.
• Existing integrity monitoring strategies face challenges with complex fault scenarios in BeiDou/Global Navigation Satellite Systems (GNSS).

Purpose of the Study:

• To propose and evaluate a novel integrity monitoring strategy, Optimal-ARAIM, for optimizing the vertical protection level (VPL) in BeiDou/GNSS.
• To enhance the robustness and reliability of navigation operations through improved integrity monitoring.

Main Methods:

• Optimal-ARAIM utilizes a minimax estimator to minimize VPL by adjusting the full-set solution and allocating integrity/continuity risks.
• A maximum monitoring order mechanism mitigates combinatorial explosion from satellite faults, formulating scenarios as a convex optimization problem.
• Performance is evaluated using BeiDou observation and almanac data, and global GNSS almanac data.

Main Results:

• The average VPL was consistently below 8 meters across five Asian stations using observation data.
• Predicted VPL distributions using BeiDou almanac data were predominantly below 10 meters.
• Global availability coverage exceeded 93%, meeting the CAT-I standard.

Conclusions:

• Optimal-ARAIM effectively reduces VPL for BeiDou/GNSS, ensuring robust and reliable navigation.
• The proposed strategy enhances navigation safety for critical applications like transportation and surveillance.
• The method demonstrates high global availability, meeting stringent international standards.