一种附加尺度因子的电离层层析新方法  

A New Algorithm for Ionosphere Tomography by Using Scaling Factor

作　　者：刘天弋 明峰[1,2] 洪峻 LIU Tianyi;MING Feng;HONG Jun(Institute of Electronics,CAS,19 West-Beisihuan Road,Beijing 100190,China;Science and Technology on Microwave Imaging Laboratory,19 West-Beisihuan Road,Beijing 100190,China;University of Chinese Academy of Sciences,19 A Yuquan Road,Beijing 100049,China)

机构地区：[1]中国科学院电子学研究所,北京市北四环西路19号100190 [2]微波成像技术重点实验室,北京市北四环西路19号100190 [3]中国科学院大学,北京市玉泉路19号甲100049

出　　处：《大地测量与地球动力学》2018年第12期1285-1290,共6页Journal of Geodesy and Geodynamics

基　　金：国家自然科学基金(61571417)~~

摘　　要：用乘法代数重构方法反演电离层电子密度时,没有GPS测量射线穿过的电离层网格的反演精度依赖于迭代初值。就此,提出一种改进的代数重构算法——附加尺度因子的代数重构算法(Scaling-ART)。将实测STEC与迭代中当前电子密度计算的STEC的比值作为基本尺度,依据电子密度的空间相关性和网格中心到观测射线的距离,对没有信号穿过的网格也计算出对应尺度进行调整,使其向真值逐渐逼近,提高反演精度。实验证实,改进的新算法相比于原有的乘法代数重构算法能够取得更好的反演精度。Using the multiplicative algebraic reconstruction technique(MART),the accuracy of ionospheric electron density in the cells without any rays traversing them depends on the initial value,which is generated by empirical model.To solve the above problem,an improved algebraic reconstruction technique is presented in the paper.In this algorithm,a basic scale is calculated as the proportion of observed STEC and reconstructed STEC in some iteration.According to the spatial correlation of electron density,scaling factors are calculated as a function of basic scale and the distance from the center of cell and GPS ray for each cell in the reconstruction area.So,the ionospheric electron density of each cell will get closer to the ground truth.Numerical experimental and actual observation tests prove that the new algorithm is superior to the original MART.

关 键 词：电离层层析 代数重构 尺度因子 空间相关性 

分 类 号：P228[天文地球—大地测量学与测量工程]