Objectives With the rapid popularization of low-cost receivers, single-frequency global navigation satellite system (GNSS) is now widely used. The cycle slip rate of a single-frequency GNSS receiver is commonly high in a complex situation. Although geometry-free (GF) model can detect some large cycle slips, it is not sensitive to small cycle slips. The geometry-based (GB) model is efficient for cycle slip detection and repair, but its success rate of detection descends correspondingly with an excessive number of abnormal satellites.
Methods By combining the advantages of GF and GB models, this paper proposes a new cycle slip detection and repair method. The proposed method firstly detects and rejects the abnormal satellites with large cycle slips by GF model, then uses GB model to detect small cycle slips and repair large cycle slips.
Results The results show that the proposed cycle slip detection and repair method can enhance the success rate if many cycle slips occur simultaneously. The success rate can be improved by approximately 50% even when the abnormal satellites reach the half or more of total numbers simultaneously.
Conclusions Compared with the traditional GB model, the proposed GF+GB model can take advantage of each model to improve the performance when multi-cycles occur.