基于SUMT修正法的差分码偏差和电离层TEC估计  

Estimation of differential code bias and ionospheric TEC based on the SUMT correction method

作　　者：廖思明 尚俊娜[1] 苏明坤 LIAO Siming;SHANG Junna;SU Mingkun(School of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,China)

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018

出　　处：《电信科学》2025年第3期154-166,共13页Telecommunications Science

摘　　要：基于球谐函数,实现区域电离层建模,并对区域差分码偏差(differential code bias,DCB)与总电子含量(total electron content,TEC)进行解算。对于格网处垂直总电子含量(vertical total electron content,VTEC)出现的异常值,提出一种序列无约束最小化技术(sequential unconstrained minimization technique,SUMT)修正法进行修正,利用国际全球导航卫星系统服务(International GNSS Service,IGS)网络的6个测站双频观测数据,建立了电离层VTEC区域模型,并估算了31天的卫星频间DCB,将估算值与电离层分析中心中国科学院(Chinese Academy of Sciences,CAS)发布的产品进行对比分析,结果显示:所有的卫星差值都在0.42 ns以内,其中87.5%的卫星差值在0.4 ns以内,78.1%的卫星差值在0.2 ns以内,频间DCB的平均偏差基本小于0.4 ns。此外,估算的全球定位系统(global positioning system,GPS)卫星DCB序列的标准差(standard deviation,STD)值小于0.1 ns。建立了经纬度范围为5°E~25°E、40°N~60°N的电离层区域模型,将VTEC建模结果与CAS发布的全球电离层地图(global ionospheric map,GIM)产品做差比较,结果显示整体时间点的差值均处于4 TECU以内,且超过90%的区域差值在2 TECU以内,表明估算的结果与CAS产品具有良好的一致性。The modeling of the regional ionosphere was implemented based on spherical harmonic functions,and the regional differential code bias(DCB)and total electron content(TEC)were calculated.To correct anomalies in verti cal total electron content(VTEC)values at grid points,a sequential unconstrained minimization technique(SUMT)correction method was proposed.Using dual-frequency observation data from six International GNSS Service(IGS)network stations,a regional ionospheric VTEC model was established,and the satellite inter-frequency DCB for one month were estimated.These estimates were compared with the products published by the ionosphere center of the Chinese Academy of Sciences(CAS),and an accuracy analysis was performed.The results show that all satellite DCB differences were within 0.42 ns,with 87.5%of the differences within 0.4 ns and 78.1%within 0.2 ns.The average deviation of the inter-frequency DCB was generally less than 0.4 ns,and the standard deviation(STD)of the estimated GPS satellite DCB sequence was less than 0.1 ns.A regional ionospheric model with a latitude and longitude range of 5°E~25°E and 40°N~60°N was established.The VTEC modeling results were compared with the GIM products released by CAS,showing that the overall time-point differences were within 4 TECU,with over 90%of regional differences within 2 TECU.The estimated results exhibit good consistency with the CAS products.

关 键 词：差分码偏差 TEC估计 电离层建模 SUMT修正法 

分 类 号：TN967.1[电子电信—信号与信息处理]