Research On Carrier Phase Cycle Slip Detection Of GNSS System

With the development of satellite navigation system,high-precision positioning has become an increasingly urgent needs.To achieve high-precision positioning process,we must use the carrier phase,and cycle slip detection and repair is the use of carrier phase for high-precision positioning of the premise.Based on the number of frequency points available to the receiver,this paper analyzes the method of cycle slip detection and its performance from the single frequency,dual frequency and triple frequency respectively.The main work is as follows:(1)The detection principle and detection performance of the polynomial fitting method,single-frequency code combination method and doppler integration method in single-frequency cycle-slip detection algorithm are systematically analyzed.The conclusions that the performance of the detection method has relationship with the specific receiver are given.The main factors influencing the detection precision of three methods are qualitatively analyzed by constructing satellite-difference observations and station-difference observations,which improves the theoretical reference for improving the detection accuracy of various methods.(2)In this paper,the principle of the ionospheric residual method and the MW combination method are introduced and their respective shortcomings are introduced.The method of combining the ionospheric residual method and MW combined method based on the minimum mean square error criterion is proposed.Using TRIMBLE receiver data,the ionospheric residual method is used to show that the original data does not contain cycle slip.Then,we add small cycle slips,special cycle slips and intensive cycle slips to improve the algorithm.The results show that: The improved algorithm can correct the small cycle slips and the special cycle slips of each frequency point correctly.For the intensive cycle,it can mark the intensive cycle slip time,and verify the effectiveness of the improved algorithm.This provides a more effective and universal method for dual-frequency cycle-slip detection.(3)The coefficient of the carrier phase combination and pseudorange / carrier phase combination of ionosphere-free constraint and geometric-free constraint is explored.Aiming at the limitation of geometric constraint of traditional tri-band cycle-slip detection algorithm,this paper proposes a polynomial fitting for the linear combination of observations,and then provides the geometric datum with the predicted value as the observed value.The advantage of this is that none of the three combinations require a pseudo-range combination to provide a geometric reference,which improves detection accuracy.Using TRIMBLE receiver data,we first use the improved algorithm to verify that the original data does not contain cycle slip.Then,the man-made join the small cycle slips,the special cycle jump and the big cycle slips,with the improved algorithm processing,successfully restoring all kinds of cycle slips.The results validated the improved algorithm's validity.