Research On GNSS RTK Positioning Algorithm Of Arc Division Cycle Slips Detection

With the development of Global Navigation Satellite System(GNSS)and the successful networking of Beidou 3 in China,GNSS has been widely used in various fields,and the demand for high-precision real-time positioning is increasing.In precision positioning,the accuracy of carrier phase positioning can reach centimeter-level pseudorange positioning which is much higher than meter-level accuracy by differential processing.RTK carrier phase observation technology is widely used in the field of high precision positioning because of its high real-time and high precision characteristics.Therefore,it is of great significance to conduct RTK positioning research and analysis for Beidou system in China.In the actual carrier phase measurement process,due to building occlusion,ionospheric changes,receiver hardware delay and other reasons will cause the receiver cycle counter jump,resulting in cycle slip,seriously affecting the positioning accuracy.So solving cycle slip problem is the premise and key to realize real-time and high precision positioning.The work and contributions of this paper are as follows:(1)Aiming at the cycle slip problem existing in the BDS-2 and BDS-3 observation data in the Beidou navigation satellite system,the BDS B1I and B3I signals are taken as the research objects to study the cycle slip detection and repair algorithm.Geometry-free(GF)and Melbourne-Wübeena(MW)combined algorithm are used to detect cycle slip.(2)In order to improve the detection rate of cycle slip,this paper proposes a new method of arc segment division,which takes the detection cycle slip as the boundary to delimit two different observation arcs.In this way,different values of cycle slips can be divided and marked.In addition,gross errors can be eliminated.Finally,cycle slip detection and all epoch analysis can be completed and repaired.By analyzing the double frequency data effect of cycle slip on code multipath observation.Experiments show that this method greatly improves the detection speed of cycle slip.(3)Based on the improved cycle slip detection and repair algorithm,the short baseline carrier phase difference positioning experiments of GPS,BDS single system and GPS/BDS dual system combination are carried out,and the positioning results are analyzed and compared.Through the analysis and comparison of BDS and GPS observation quality,it can be concluded that the spatial geometric distribution of BDS in the Asia-Pacific region is more reasonable,reflecting the application advantages of BDS in the Asia-Pacific region.By analyzing the positioning accuracy results,the experiment shows that the positioning error of BDS and GPS is close,which can meet the needs of high precision positioning.Compared with single system,BDS/GPS dual system has obvious advantages in positioning accuracy.RTK positioning of multi-system can bring better positioning service to users in practical application.