Kinematic GNSS Cycle-slip Detection And Repair Method With Track Information Constraints

The pole,overhead lines and noise barrier along the high speed railway may cause more frequent cycle-slip,and the cycle-slip is an important factor affecting the carrier phase positioning accuracy.In kinematic measurement,the measurement environment is relatively complex.Therefore,fast and accurate cycle-slip detection algorithm is the prerequisite for establishing a correct kinematic GNSS positioning model.Firstly this thesis introduces the basic theory of kinematic GNSS cycle slip detection and repair,briefly introduces the basic observable of GNSS positioning and its linear combinations,and briefly analyzes the basic theory of the cycle-slip detection,and then introduces the Kalman filtering model,the linearization of the observation equation and the determination of the initial value of the Kalman filtering;In the end,the process of track measurement and kinematic measurement is introduced,and constraints conditions are introduced,including line constraints and curve constraints,and the establishment process,method and model of constraint conditions are given.The constraints are added to the Kalman filtering equation,and the constraint Kalman filtering equation is formed.Using track information as constraint conditions,the prediction value of Kalman filtering equation can be corrected,so that the accuracy of cycle-slip detection can be improved.In this thesis,the Kalman filtering with track constraints can be used to detect the mid cycle-slip,large cycle-slip,multi-cycle-slip and continuous cycle-slip under the kinematic condition,and the cycle-slip detection for different satellite elevation angles.The experimental results show that the detection precision of the Kalman filtering after the constraint for mid cycle-slip and large cycle-slip is improved,and the constraint Kalman filtering makes up for the defect that the standard Kalman filter cannot detect the continuous cycle-slip,and can deal with the problem of multi-cycle-slip and continuous cycle-slip,and after the constraint conditions are added,Kalman filtering has faster convergence rate and improved kinematic cycle-slip detection effect.This paper also discusses the detection of the cycle-slip of different satellite height angles.The effect of the cycle-slip detection will be influenced by the elevation angle of the satellite.With the increase of the elevation angle of the satellite,it is more advantageous to the precision of the cycle-slip detection.