基于IRI背景场的单站电离层TEC地图重构技术

Technique of Reconstructing Ionospheric TEC Map With the Data of Single Station Based on the Background Field by Using IRI

为了有效解决电离层TEC观测数据稀疏时重构问题,引入IRI-2007作为背景场,利用反距离加权法和克里格方法重构了电离层TEC地图,使用交叉检验方法检验了引入背景场前后的重构精度.结果表明,引入背景场后,一方面有效地控制了边缘地区的发散现象,另一方面重构网格点上绝对误差在-0.25～0.25 TECU之间的比例分别提高了约70%和100%,误差统计基本呈正态分布.

Owing to the sparse data, the reconstructing ionospheric maps are not accurate enough by using the interpolation methods directly, especially in the verges. In order to obtain better TEC maps, the reconstruction was performed by Inverse Distance Weighting and Kriging Methods with IRI-2007 used as the background field. The test produced a better performance according to using Cross-validation method. As a result, the new technique decreased the errors effectively, especially in the verges, and the proportions of absolute errors between -0.25-0.25TECU at all grid points in the reconstructing ionospheric map were improved by 70% and 100%. Meanwhile statistic errors showed a normal distribution. The reconstructed precision can be improved by using more exact background or successive correction method.