A Network Real-Time Kinematic Method for GPS and BDS Double Systems Between Long Range

The uncertainty of distance-related error of global navigation satellite system is gradually increasing with the increase of distance between the reference stations and the rover station. Therefore, the dual-systems of global positioning system (GPS) and BeiDou satellite navigation system (BDS) network real-time kinematic (RTK) method was presented to meet the demand of high-precision long range positioning RTK. Firstly, the wide-lane ambiguities were fixed by the multi-frequency observation data of GPS and BDS between long-range reference stations. The satellite clock errors can be eliminated by the double-difference solution model, simultaneously the atmospheric error and satellite orbit errors can be weakened. Then the double-difference carrier phase integer ambiguities can be fixed by the resolution model including atmospheric error and carrier phase ambiguity. The method of classification error corrections between long-range reference stations network was used. The observation errors were classified, according to the characteristics of observation errors between long-range reference station network. The ionosphere errors and non-dispersive errors of the rover station were calculated by using the reference stations' error correction and regional error interpolation. The atmospheric errors and satellite orbit errors of the rover station can be weakened by the method of interpolation. Then the errors of GPS/BDS carrier phase observation of the rover station were removed by the calculation errors. The carrier phase integer ambiguities of the rover station can be fixed by the method of resolution integer ambiguity with multi-frequency carrier phase, and the position of the rover station was obtained by the fixed ambiguities. The algorithm validation was carried out by the data on long-range reference station network. Three long-range reference stations and one rover station were used to test in Central China. The positioning accuracy of centimeter can be obtained by the algorithm of dual-systems of GPS and BDS network RTK. At the same time, single system can also get the centimeter level of position and the GPS is better than BDS. The method of dual-systems of GPS and BDS network RTK can guarantee the positioning accuracy of the rover station. The results of experiment indicate that the GPS/BDS long-range network RTK can be realized and the centimeter level positioning accuracy can be achieved by this algorithm.