自相关分析法用于电离层TEC的内插评估

基于2004年实测数据的统计分析，将自相关分析法用于电离层TEC的缺值内插，并进行精度评估.采用上海地区GPS综合应用网和中国地壳运动GPS监测网数据，解算成电离层垂直TEC，对缺值进行了时序内插及评估.结果表明，缺值段内的插值误差一般中间较大，两侧较小，插值误差远小于均方差.将自相关分析法内插结果与线性插值法、抛物线法、三次样条法内插结果进行对比，发现对于缺值较多、变化较复杂的缺值段，其插值精度有明显的提高.采用自相关方法进行内插后，有效减小了由于缺值而引起的局部跳跃变化，可以比较准确地研究TEC变化特性. 

Interpolation Evaluation of Ionospheric TEC Based on Autocorrelation Analysis Method

In the ionospheric TEC monitoring system, there are often multiple, long-term missing values in one day, which have an impact on the study of the spatio-temporal variation characteristics of the ionospheric TEC. Based on the statistical analysis of measured data in 2004, ionospheric TEC interpolation and accuracy evaluation are studied by using of autocorrelation analysis method. Using the data of the Shanghai GPS integrated application network and the Chinese crustal movement GPS monitoring network, it is converted into the vertical TEC of the ionosphere, and the missing values are time-interpolated. The results show that the interpolation error in the missing value segment is generally larger in the middle, while smaller on both sides, and the interpolation error is much smaller than the mean square error. The interpolation results of autocorrelation analysis method are compared with the results of linear interpolation, parabolic method and cubic spline interpolation method. It is found that the accuracy of interpolation is obviously improved for the missing value segment with relatively complex changes. After the interpolation, the jump change caused by the missing value is effectively reduced by the autocorrelation method and the TEC variation characteristics can be studied more accurately.