In single-frequency precise-point positioning of a satellite,ionosphere delay is one of the most important factors impacting the accuracy. Because of the instability of the ionosphere and uncertainty of its physical p...In single-frequency precise-point positioning of a satellite,ionosphere delay is one of the most important factors impacting the accuracy. Because of the instability of the ionosphere and uncertainty of its physical properties, the positioning accuracy is seriously limited when using a precision-limited model for correction. In order to reduce the error, we propose to introduce some ionosphere parameter for real-time ionosphere-delay estimation by applying various mapping functions. Through calculation with data from the IGS（ International GPS Service） tracking station and comparison among results of using several different models and mapping functions, the feasibility and effectiveness of the new method are verified.展开更多
基金supported by the National Natural Science Foundation of China(40902081,40774001,40841021)
文摘In single-frequency precise-point positioning of a satellite,ionosphere delay is one of the most important factors impacting the accuracy. Because of the instability of the ionosphere and uncertainty of its physical properties, the positioning accuracy is seriously limited when using a precision-limited model for correction. In order to reduce the error, we propose to introduce some ionosphere parameter for real-time ionosphere-delay estimation by applying various mapping functions. Through calculation with data from the IGS（ International GPS Service） tracking station and comparison among results of using several different models and mapping functions, the feasibility and effectiveness of the new method are verified.
文摘电离层延迟可严重制约单频接收机的定位精度.基于此,本文介绍了四种单频接收机常用的电离层延迟改正方法,包括广播电离层改正模型(策略1),顾及太阳位置的变化全球电离层格网产品(Global Ionosphere Map,GIM)时间旋转内插(策略2),GIM投影函数改正(策略3)和半合改正模型(策略4).同时,选择不同太阳活动期,不同纬度的测站验证不同电离层改正方法的单频精密单点定位(single-frequency point positioning,SF-PPP)定位结果偏差.经过对比分析,得到如下结论:1)总体来说,半合改正模型得到的定位效果最佳,其次是使用GIM产品对电离层延迟进行改正,最后是广播电离层模型;2)在不同太阳活动跃期,不同策略在低纬度测站的定位偏差最大,其次是高纬度测站,中纬度测站的定位偏差最小;3)策略2和策略3在不同太阳活动期不同纬度测站的水平定位平差约0.150 m,三维定位偏差约0.700 m;策略4在不同太阳活动期不同纬度测站的水平定位偏差为0.100 m,三维定位偏差为0.500 m.
