Research On Pseudo-single Point Positioning Algorithm For BDS/GPS Combined System

Beidou satellite navigation system by independent research and development is the third global navigation and positioning system after the US's GPS and Russia's GLONASS system.Currently,the United States is on the modernization transformation of GPS,GLONASS system keeps a positive,continuous improvement and development.With rapid development of BDS and GALILEO system,the satellite navigation system gradually formed GPS,GLONASS system,BDS and GALILEO system four navigation systems compete with each other,compatible situation.Under this background,the accuracy of static single point positioning for global navigation and positioning system which can be used in China is studied,including single point positioning of GPS or BDS and single point positioning of BDS/GPS combined navigation system.Firstly,the main error source and error correction model in the single point positioning process is analyzed,and uses the error correction model to calculate the corresponding error correction value,which provides a solid guarantee for the subsequent single point positioning solution.Secondly,According to the actual observation data provided by the IGS Center of Wuhan University,the accuracy of the single-point positioning of GPS and BDS is calculated by GPS and BDS single-point positioning principle respectively,and the positioning performance of two kinds navigation system in the Asia-Pacific region are compared and analyzed,and then analyze the reasons.Furthermore,the single point positioning accuracy of BDS/GPS combined navigation system is further studied by using measured data in this paper.The experimental results show that the positioning performance of BDS/GPS combined navigation system is significantly improved compared with single system.Therefore,the combined navigation is a major trend in the future development of navigation,it is worth for our in-depth study.In the end,how to improve the positioning accuracy of the combined navigation system is further studied in this paper.We analyze several commonly used models of the observed value,and compare the several models to get the best weighting model.