A New Algorithm for High-Integrity Detection and Compensation of Dual-Frequency Cycle Slip under Severe Ionospheric...

Area of Science:

• Geomatics Engineering
• Satellite Navigation Systems
• Signal Processing

Background:

• Dual-frequency cycle slips degrade carrier-phase positioning accuracy.
• Existing methods like Melbourne-Wübbena (MW) are susceptible to multipath and ionospheric disturbances.

Purpose of the Study:

• To develop a robust algorithm for detecting and repairing dual-frequency cycle slips in network-based RTK systems.
• To enhance the integrity and reliability of high-precision positioning under adverse conditions.

Main Methods:

• Utilized two independent carrier-phase combinations (ionospheric negative and positive) to avoid insensitive pairs.
• Applied second-order time differences to mitigate ionospheric delay impacts, even during storms.
• Incorporated a LAMBDA-based method for cycle slip compensation.

Main Results:

• Achieved high integrity with a missed detection probability of 7.5 × 10^-9 at a 10^-5 false-alarm rate.
• Demonstrated a cycle slip compensation failure rate of 1.4 × 10^-8.
• Successfully detected and compensated for artificially inserted cycle slips during severe ionospheric storm simulations.

Conclusions:

• The proposed algorithm effectively handles dual-frequency cycle slips in network RTK systems.
• The method ensures high integrity and reliable positioning performance.
• It offers a significant improvement over legacy methods, especially in challenging environments.