Reconstruction Method for the Ionospheric f₀F₂ at High Latitude Region Based on Kriging Method with Geomagnetic Coordinates

As an important part of the solar space environment, the ionosphere state exerts significant impacts on human communication and satellite navigation. The current approach of this modified Kriging reconstruction accuracy of the existing methods needs to be improved. In order to improve the reconstruction accuracy of the ionospheric critical frequency of F₂ layer (f₀F₂) over high latitude regions, a method combining geomagnetic coordinates with modified Kriging interpolation is proposed. A variogram is determined by comparing two types of coordinate systems, two types of ionospheric distance calculation methods and different scale factors. The ionospheric critical frequency is estimated by solving this variogram-related Kriging equation. Cross-validation is implemented on observations recorded during solar maximum activity year (2013) and solar minimum activity year (2017), of four seasons in day and night, and with different scale factors at six ionospheric sounding stations over Russian region. Experimental results showed that the standard errors of the three methods are distributed within 1MHz, and the reconstruction error of the proposed method is reduced compared to the previous methods. Hence the effectiveness of the selected geomagnetic coordinate is verified. In summary, the proposed reconstruction method is of great significance for improving usable frequency prediction and enhancing communication performance.