Research Of Reconstruction Method For Ionospheric Parameter Based On Geomagnetic Coordinates

As an important part of the solar space environment,the ionosphere state exerts significant impacts on human communication and satellite navigation,and it also provides guidance for disaster warning.However,due to the many factors affecting the ionospheric parameters,the ionospheric state is complex and variable,in order to make better use of the ionosphere and provide services for related applications,it is necessary to carry out research on ionospheric parameters.This dissertation focuses on solving the problems of reconstruting the highprecision ionospheric parameters.The main purpose is to use the modified Kriging method to estimate the real-time distribution of the critical frequency of the F2 layer in the local ionosphere using the ionospheric data of 13 vertical detection stations in the high latitudes of the northern hemisphere and the middle and low latitudes of the southern hemisphere.The current approach of this modified Kriging method is to establish a variogram and reconstruct ionospheric parameters by using the corrected Euclidean distance in geographic coordinates.However,the reconstruction accuracy of the existing methods needs to be improved.For this purpose,this thesis proposes a modified Kriging method based on geomagnetic coordinates,which reconstructs high-latitudes,the middle and low latitudes regions using the detected ionospheric f_oF₂ data from 2013 to 2017.This method was determined by comparing two types of coordinate system,two types of ionospheric distance calculation methods and different scale factors;Following this,three variograms under the modified Kriging method were used to cross-validate and compare the solar activity high years and the solar activity low years,four seasons and day and night reconstruction results in the high latitudes of the northern hemisphere and the middle and low latitudes of the southern hemisphere.The results show that the standard error of the three methods are distributed within 1MHz.As a reulst,the adoption of the large circle distance greatly improves the optimization performance the modified Kriging method,which not only verifies the effectieness of the geomagnetic coordinate based method but also reveals that the proposed reconstruction method outperforms the existing methods.