利用半参数核估计的电离层建模新方法  

A New Method of Ionospheric Modeling Based on Semi-Parametric Kernel Estimation

作　　者：蒋可 潘雄[1] 罗小敏 李扬[1] 张旭焱 徐景田[1] JIANG Ke;PAN Xiong;LUO Xiaomin;LI Yang;ZHANG Xuyan;XU Jingtian(School of Geography and Information Engineering,China University of Geosciences,Wuhan 430079,China)

机构地区：[1]中国地质大学地理与信息工程学院,湖北武汉430079

出　　处：《武汉大学学报（信息科学版）》2023年第9期1416-1424,共9页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41874009)。

摘　　要：目前区域电离层延迟建模中,较少顾及单层模型薄层高度假设误差、投影函数选择误差、差分码估计偏差以及数学公式的模型化误差等,为了削弱这些误差对解算精度的影响,将半参数模型引入到电离层球谐函数建模中,利用半参数核估计方法,解算误差分量和球谐函数系数,并将解算结果代入区域4阶电离层球谐函数计算建模区域内电离层总电子含量(total electron content,TEC)。选取欧洲大陆区域的国际GNSS服务组织(international global navigation satellite system service,IGS)测站,分别对太阳活动低年和太阳活动高年的观测数据进行电离层建模,并采用半参数核估计法与传统最小二乘法进行建模精度的对比与分析。实验结果表明:太阳活动低年,以欧洲定轨中心发布的电离层TEC为参考,利用半参数核估计法的区域电离层建模相比于最小二乘,其精度提高了12.2%~19.0%,以IGS发布的电离层TEC为参考,其精度提高了8.3%~13.6%;太阳活动高年,利用半参数核估计法进行电离层建模相较于最小二乘法精度相当。Objectives:At present,in the modeling of regional ionospheric delay,the assumption error of thin layer height,the selection error of projection function,the estimation error of differential code bias and the modeling error of mathematical formula are seldom considered.In order to reduce the influence of these errors on the calculation accuracy,a semi-parametric model is introduced into the modeling of spherical harmonic function in the ionosphere,the results are substituted into total electron content(TEC) of the ionosphere in the modeling region by the fourth-order ionospheric harmonics function.Methods:The modeling accuracy of 24 international global navigation satellite system service(IGS) stations in the European continent and 48 stations in China is compared and analyzed by using the semi-parametric kernel estimation method and the traditional least square method.Results and Conclusions:Experimental results show that compared with the least square method,the accuracy of regional ionospheric modeling based on semi-parametric kernel estimation method is 12.2%-19.0% higher than that based on the ionospheric TEC published by Center for Orbit Determination in Europe(CODE) and 8.3%-13.6% higher than that based on the ionospheric TEC published by IGS in low solar activity years.Compared with the least square method,the semi-parametric kernel estimation method has the same accuracy in ionospheric modeling due to high solar activity.

关 键 词：电离层建模 半参数模型 球谐函数 

分 类 号：P228[天文地球—大地测量学与测量工程]