利用地统计方法研究了全球VTEC时空分区特征,提出了IONEX单天产品发布的改进策略和VTEC时空分区建模方法,包括组合函数与IRI2007模型背景场建模方法。纬度10°~70°、经度60°~180°范围内单天VTEC分区建模与结果分析表明,分区建模极大地降低了模型的复杂性。上述两种方法均可得中低纬分区B13约为高纬分区A23中误差(2~3TECU)的2倍,验证了顾及VTEC时空特征分区建模的有效性。
Based on geostatistics principal,the global spatial-temporal partition features are investigated detailedly using IONEX products derived from IGS.Moreover,release policy of IONEX products is provided for IGS.Then,VTEC partition modeling methods which include both combination function method and IRI2007 background field method are presented.In the end,VTEC modeling results and analysis show that partition modeling greatly reduces the complexity of the model,and VTEC RMSE of low latitude partition B13 is invariably about two times that of high latitude partition A23 for two methods.So,VTEC partition modeling is proved to be effective and reliable.