Research On The Optimization Of Ionospheric Error Correction Algorithm For Beidou System

Satellite navigation plays an increasingly important role in aviation.Improving the positioning accuracy of my country’s Beidou system is very urgent for improving the application of satellite navigation in civil aviation.For this reason,the main error sources that affect the accuracy of the Beidou satellite system have been studied,and the model has been established to make corrections.It is found through research that the ionospheric error is an important factor influencing the accuracy of satellite positioning.A correction model of the ionosphere is proposed,which is verified by the integrity simulation experiment.A detailed description of the components and working principles of the Beidou system.The main error sources that affect the positioning accuracy of the Beidou system are discussed and studied,and a correction method is proposed.The ionospheric delay,which is the most serious error source affecting the positioning accuracy,is analyzed,and different ionospheric delay correction models are proposed for single-frequency users and dual-frequency users.By using the improved Klobuchar model to simulate the single-frequency user ionospheric delay,good results are obtained.The working principle of the ground-based and satellite-based augmentation system is introduced,and the monitoring station plays an important role in the ground-based and satellite-based augmentation system.The grid ionosphere model is used for dual-frequency users.The control center under this model proposes inverse distance weighting,bilinear interpolation and KRG interpolation,and uses three-point interpolation and four-point interpolation for users.When improving the ionospheric delay,the MATLAB simulation platform was used to simulate and compare these methods,and the best interpolation model was obtained.The three integrity indicators of UDER,RURA,and GIVE were used to verify the positioning accuracy of the ionospheric correction model.The integrity of the MEO satellites of the Beidou-2 and Beidou-3 systems was selected for simulation.Through the analysis of the simulation results,it is verified that the error between UDER and RURA is within the allowable range and can meet the needs of users.For the GIVE value,the grid points are selected for calculation,and the integrity of the GIVE is used to verify that the error obtained by the Kriging interpolation method is within the allowable range.