Real-Time Cycle Slip Detection in Single-Frequency GNSS Receivers Using Dual-Index Cross-Validation and...

Area of Science:

• Geomatics Engineering
• Satellite Navigation Systems
• Signal Processing

Background:

• Cycle slips in carrier-phase measurements are a major obstacle for single-frequency GNSS receivers, especially in real-time scenarios.
• Single-frequency receivers lack the redundant measurements of dual-frequency systems to easily detect cycle slips.
• Rapid and reliable cycle slip detection is crucial for the integrity of GNSS positioning.

Purpose of the Study:

• To develop and validate a real-time cycle slip detection algorithm for single-frequency GNSS receivers.
• To achieve high detection accuracy and minimize false positives without external data.
• To provide a robust solution for applications requiring precise real-time GNSS data.

Main Methods:

• A novel algorithm utilizing short-term differencing of pseudorange and carrier-phase observables.
• A two-step detection logic involving first-order differencing of code-minus-carrier and second-order differencing of carrier phase.
• Implementation of satellite elevation-dependent adaptive thresholds for robust performance across various signal conditions.

Main Results:

• The algorithm demonstrated over 98% detection accuracy for cycle slips larger than 10 cycles in experimental tests.
• Achieved zero false positives during artificial slip testing, indicating high reliability.
• Showed 87.93% agreement with receiver Loss of Lock Indicators (LLI) during periods of signal instability.

Conclusions:

• The proposed algorithm offers an effective, real-time solution for cycle slip detection in single-frequency GNSS receivers.
• It operates independently of user position, receiver flags, or additional sensors, simplifying integration.
• The method provides a robust and accurate tool for improving the reliability of single-frequency GNSS applications.