Influence of three ionospheric models on navigation positioning accuracy in China

Ionospheric delay error is one of the most important errors in navigation and positioning. Ignoring the effects of the second and the upper order terms of the ionosphere, dual-frequency/multi-frequency receivers eliminate the effects of ionospheric delay error through ionosphere-free combination model, while single frequency receivers can only weak the ionospheric delay error through the ionospheric model parameters broadcasted by satellite navigation and positioning systems. In the current major satellite navigation systems, GPS uses the Klobuchar ionosphere model, BDS uses the improved Klobuchar ionosphere model, and Galileo uses the NeQuick ionosphere model. Analysing the influence of GPS Klobuchar model, BDS Klobuchar model and NeQuick model on navigation and positioning accuracy in China has great significance to guide the single frequency receivers in China to select the suitable ionospheric parameters broadcasted by satellite navigation and positioning systems. In this paper, GPS L1 single-frequency observation data of 8 sites in Crustal Movement Observation Network of China are used, the GPS Klobuchar model, BDS Klobuchar model and NeQuick model are selected for single point positioning. The final positioning results are compared to evaluate the correction accuracy of the three models in China. The results show that choosing the NeQuick ionosphere parameters in China is more conducive to improving the navigation positioning accuracy in the region, followed by selecting the BDS Klobuchar ionosphere parameters and finally selecting the GPS Klobuchar ionosphere parameters.