Research On Corrected Higher-Order Ionospheric Delay Error With Geomagnetic Effect

This paper describes systematically the fundamental knowledge of ionosphere and geomagnetism. It introduces the theory of electromagnetic wave propagating within the ionosphere and geomagnetism, then expounds the correcting methods of the ionospheric delay error and the ionospheric model in common use and their efficiency. The formula of correcting higher-order ionospheric error is deduced by Appleton-Hartree formula, and the triple-frequency corrected model is deduced too. That carrier phase and pseudo-ranges observations corrected ionospheric error with triple-frequency liner combination is compared , then discussed the feasibility analysis. It put forward a new project to correct the second-order ionospheric error by considering the geomanetic effect. If it make use of International Geomagnetic Reference Field- 2005 coefficient to compute space geomagnetic vector, we can estimate the second-order ionospheric delay error by dual-frequency observation. In order to overcome the shortcoming of complicated algorithm, the author advanced the method that apply quadraric surface fit space geomagnetic vector to estimate the second-order ionospheric delay error.Based on the forenamed theory, Estimated the Total Electron Content including the second-order ionospheric error. Established the 2° ×2° geomagnetic vector grid-model over mostly area of China , then processed some dual-frequency data to indicate the algorithm is feasible and correct. Obtained some useful conclusion after analyzing the result of data processing.