Improved Method to Detect and Repair Cycle Slip for GNSS Medium–Long Baseline in Real-Time Marine Surveys

ABSTRACT

Distance-related errors complicate the resolution of real-time ambiguity in medium–long baseline marine surveys. Therefore, detection and recovery of cycle slips in real time is required to ensure high accuracy of global navigation satellite system positioning and navigation in marine surveys. To resolve this, an improved method was presented, where linear combinations of the triple-differenced (TD) between carriers L₁ and L₂ were formed for a wide lane and free ionosphere. To overcome severe ill-conditioned problems of the normal equation, the Tikhonov regularization method was used. The construction of a regularized matrix by combining a priori information of known coordinates of reference stations, followed by the determination of the corresponding regularized parameter are suggested. A float solution was calculated for the TD ambiguity. The search cycle slip (TD integer ambiguity) was obtained using the least-squares ambiguity decorrelation adjustment (LAMBDA) method. Using our method, cycle slips of several reference station baselines with lengths of a few hundred to one thousand kilometers were detected in real time. The results were consistent with professional software, with a success rate of 100%.

KEYWORDS:

• Cycle slips
• GNSS
• ill-conditioned
• medium–long baseline marine surveys
• real-time detection and repairing

Acknowledgements

The data used here were provided by the Crustal Motion Observation Network of China and the National CORS in the Michigan area network of the USA. We would like to thank the editor in chief, associate editor, and reviewers for suggestions that improved this paper.

Additional information

Funding

The authors would like to thank the National Natural Science Foundation of China (Grant Nos. 41374043 and 41574015) and the Chinese Polar Environment Comprehensive Investigation and Assessment Programmes CHINARE (2016-03-03 and 2016-04-03) for the financial support.