Research On RTK Positioning Performance Of Bei Dou Navigation Satellite System

With the development of science and technology and the maturity of satellite systems in various countries,the technology of using satellite systems for high-precision positioning is emerged.When positioning based on satellites,the available satellite signal observations including pseudorange observations and carrier phase observations.The positioning result based on the carrier phase observation is much more precise than that based on the pseudorange.At present,the commonly used RTK carrier phase difference technology can obtain real-time high-precision centimeter-level positioning information by real-time differential processing of carrier phase observations of two stations.BeiDou Navigation Satellite System is constructed and operated by China independently,and it has great significance in researching the real-time kinematic based on BeiDou Navigation Satellite System.Based on the extended kalman filter algorithm,the RTK software is designed to perform RTK positioning calculation on the measured BDS and GPS data underneath different satellite configuration and site conditions.The single-frequency and dual-frequency RTK positioning performance of BDS single system and BDS/GPS dual system are analyzed from satellite visibility,PDOP,positioning error and positioning accuracy,ambiguity fixed rate and time availability.In the dynamic baseline scenario,data of three different speeds are collected and analyzed.The experimental results show that whether it is single system or dual system RTK positioning,centimeter-level positioning accuracy can be obtained in E,N and U directions.The BDS has the smallest positioning error in the E direction.In the three positioning modes of BDS,GPS and BDS/GPS,the BDS has the highest ambiguity fixed rate,which indicates that the time required for the BDS to re-fix the ambiguity is short.So the BDS has a high fixed rate of ambiguity and can be used for real-time applications.