基于地磁坐标和Kriging技术的高纬地区f0F2重构方法

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

为能够在高纬区域获取高精度电离层参数特性结果,提出了基于地磁坐标的高纬度区域电离层F2层临界频率(f0F2)的重构方法.该方法确定了基于地磁坐标的变异函数,通过求解改进Kriging方程得出估计值.方法的确定取决于对2种坐标系、2类电离层距离计算方法以及尺度因子的选取.通过对俄罗斯6个垂直探测站在太阳活动高年(2013年)和低年(2017年)的f0F2历史观测数据使用月中值进行交叉验证,证明了引入地磁坐标和利用球面距离计算方法对高纬度地区进行重构能够达到最优效果.相比现有方法,其整体标准误差和绝对误差均有所降低.上述研究证实了该方法的有效性,对电子信息系统的可用频率预测以及通信效能保障具有重要意义.

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 1 MHz,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.