Research On GNSS Cycle Slip Detection And Repair Method

At present,GNSS is developing in many directions,and the realization of high precision measurement and positioning of research objects is one of the hot issues in GNSS research.In high precision positioning,in order to achieve the accuracy of positioning,it is necessary to ensure that the receiving equipment receives correct and complete observation data.The missing,abnormality and inconsistency of observation data with the original data will lead to errors in the subsequent analysis of the observations,making the positioning inaccurate.In order to judge whether the data is applicable or not,the quality of the data needs to be analyzed.In addition,there are cycle slips in carrier phase measurements in data processing,which may lead to inaccurate ambiguity resolution.Therefore,this thesis focuses on the analysis and research of the test quantity of the observed data and the jump in the carrier phase observation value.The main contents are as follows:(1)Briefly introducing the principle of data observation and its combined model,the principle and impact of cycle slip generation.The principle of multi-data inspection quantity and its verification method are analyzed in detail,including the effects of multi-path,signalto-noise ratio and clock hopping on the observed data.Explain the correlation between elevation angle,multipath and signal-to-noise ratio,and the amount of error caused by clock hopping in the receiving device for satellite positioning.(2)Several models of cycle slip detection and repair algorithms for single-frequency data are discussed and analyzed.The common detection methods such as high-order difference method,wavelet analysis method and Doppler method are introduced in detail,and the situation of these methods at different sampling intervals is analyzed.In addition,a variety of cycle slip detection and repair models for dual-frequency data are studied and analyzed.The principles of ionospheric residual method,TurboEdit method and MW method and detection performance are analyzed in detail to verify the application of the algorithm model and the detection accuracy.(3)Aiming at the influence of sampling interval on the detection accuracy of observation data,an improved algorithm model is established.Firstly,Lagrange interpolation method is used to interpolate the data,and then polynomial fitting is used to fit the carrier phase data.Secondly,the cycle slip is detected and repaired by Doppler integral method.Finally,the feasibility of the algorithm is verified by experiments.Through experimental comparison,the number of cycle slips detected by the algorithm model is about 3 times and 4 times higher than that of the traditional Doppler integration method at 5s and 10 s sampling intervals,and the detection accuracy is increased by 20% and 30% respectively.(4)Aiming at the problem of insensitive cycle slip,and based on the characteristics of Doppler stability,the data model is established by the joint Doppler integration method and MW method to realize the separation of the phase-cycle hop values of the dual-frequency carrier.The simulation results show that the model can detect and repair sensitive cycle slips,continuous cycle slips and wild values.The experimental comparison shows that the proposed method improves the detection rate of sensitive cycle hops in the MW combination algorithm by 100%.