Global Ionospheric Modeling and Positioning Accuracy Analysis with IRI Model Constraints

Abstract:

The effectiveness and necessity of adding International Reference Ionosphere （IRI） model constraints and different data selection strategies are determined in the global ionospheric modeling with the carrier-to-code leveling method. The experimental analyses show that by using the original dual-frequency P₁ and P₂ observations with IRI model constraints， the overall effect of ionospheric modeling is significantly improved at some epochs. Specifically， in those areas where observations are insufficient， the positioning errors are significantly reduced by 0.260 m， 0.146 m， and 0.103 m in the North， East， and Up directions respectively， which verifies the effectiveness of the method. After replacing the missing P₁ observations with C₁ observations as low-accuracy data， the overall quality of ionospheric modeling is further improved， although the model accuracy is slightly lost. In areas without sufficient observations， the positioning errors are increased by 0.524 m， 0.111 m， and 1.549 m in the North， East， and Up directions respectively， indicating the necessity of using the P₁ and P₂ dual-frequency observation data.

Key words:GNSS (Global Navigation Satellites System);global ionosphere;IRI (International Reference Ionosphere) model;spherical harmonics;positioning accuracy