Real-Time Quadruple-Frequency Cycle Slip Detection and Repair Algorithm Based on the Four Chosen Linear Combinations

Abstract

GNSS is now being speedily expanded to our daily life, but the positioning precision still can hardly meet the demands of many high-precision applications, such as approaching landing system on airports. Due to the development of GNSS, quadruple-frequency signals are now available in China's BeiDou Navigation Satellite System (BDS) and the European Galileo system, which can contribute to positioning precision. Positioning precision can not be improved obviously by quadruple-frequency carrier phases until cycle slips are detected and repaired. A method using four linear combinations to detect and repair quadruplefrequency cycle slips is proposed in the paper. The choices of the four linear combinations are conducted in cascaded steps in accordance to the cycle slip fixing probability. When the four detection combinations are determined, cycle slips on original carrier phase observations can be uniquely determined. The proposed algorithm has been tested on real 30-second quadruple-frequency static observations of BDS and Galileo and on real 0.05-second quadruple-frequency kinematic observations of BDS and Galileo. Simulated and real cycle slips are tested. The results show that the proposed algorithm can detect and repair cycle slips even for one cycle effectively.INDEX TERMS Quadruple-frequency observations, cycle slip, linear combination, BDS, Galileo.

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Real-time cycle slip detection and repair for BDS-3 triple-frequency and quad-frequency B1C/B1I/B3I/B2a signals

“…Compared to BDS-2, BDS-3 satellites broadcast two new open service signals B1C and B2a which are compatible and interoperable with other GNSS (Wang et al, 2019;Fan, et al, 2020). Although some scholars have performed cycle slip detection and repair based on the BDS-3 triple-frequency and quad-frequency observations, they do not fully consider the impact of ionospheric delay and choose the optimal combination way leading to weak sensitivity of cycle slip detection and low success rate of cycle slip repair (Yang et al, 2019;Zhang, et al, 2019;Shi, et al, 2020).…”