用Kriging方法构建中纬度区域电离层TEC地图

Central and Northern China TEC Map Using the Kriging Method

提出了中国中北部及周边(30°N～55°N,70°E～140°E范围内)区域电离层电子浓度总含量(TEC)地图(简称CNC TEC Map)的Kriging算法.比较了目前被广泛使用的电离层模型(Klobllchar,IRI和JPL GIM)与真实的TEC分布的符合情况;比较了常数漂移(普通Kriging方法)、线性漂移和二次漂移的Kriging方法;在三种不同的时间分辨率(5min,30min和120min)下,比较了Kriging算法、就近插值算法和多项式回归算法(5阶)绘制CNC TEC Map的效果.结果显示在本文研究区域内常用的电离层模型与真实TEC分布存在较大的区别;使用普通Kriging方法就可以较好的表示华北地区TEC分布;Kriging方法的结果优于其余两种插值算法,尤其是当时间分辨率提高到5min时,Kriging算法的优势比较明显.

In this paper the Kriging method was introduced to map Central and Northern China （30°N-55°N, 70°E-140°E） Total Electron Content （TEC） Map （CNC TEC Map）. Firstly, three popular ionosphere models （Klobuchar model, IRI and JPL GIM） were compared with grid TEC. Then CNC TEC Map using Kriging method with constant drift, linear drift and quadratic drift were compared with each other. Then TEC map derived from nearest neighbor method, polynomial regression method （order=5） and Kriging method with different temporal resolution of 5 minutes, 30 minutes and 120 minutes were compared. The result revealed that even in the mid-latitude area, these popular ionosphere models showed great differences from observation; that the results of the Kriging algorithms were similar which led us go use ordinary Kriging method, i.e. Kriging method with constant drift; and that the Kriging method was begger than other methods, especially when temporal resolution was high.