测绘学报 ›› 2018, Vol. 47 ›› Issue (S0): 45-53.doi: 10.11947/j.AGCS.2018.20180299

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电离层二阶项延迟对GPS动态精密单点定位的影响

张绍成1,2, 王鑫哲1,3, 黄龙强1, 殷飞1   

  1. 1. 中国地质大学信息工程学院, 湖北 武汉 430074;
    2. 大地测量与地球动力学国家重点实验室, 湖北 武汉 430077;
    3. 武汉大学测绘学院, 湖北 武汉 430079
  • 收稿日期:2018-06-26 修回日期:2018-07-24 出版日期:2018-12-31 发布日期:2019-05-18
  • 作者简介:张绍成(1982-),男,博士,讲师,研究方向为GNSS精密定位与GNSS掩星大气反演。E-mail:gnss.zsc@foxmail.com
  • 基金资助:
    国家自然科学青年基金(41504023);大地测量与地球动力学国家重点实验室基金(SKLGED2015-3-2-E)

Impact of Second Order Ionosphere Delays for GPS Kinematic Precise Point Positioning Applications

ZHANG Shaocheng1,2, WANG Xinzhe1,3, HUANG Longqiang1, YIN Fei1   

  1. 1. Faculty of Information Engineering, China University of Geosciences, Wuhan Campus, Wuhan 430074, China;
    2. State Key Laboratory of Geodesy and Earth's Dynamics, Wuhan 430077, China;
    3. School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China
  • Received:2018-06-26 Revised:2018-07-24 Online:2018-12-31 Published:2019-05-18
  • Supported by:
    The National Natural Science Foundation of China(No. 41504023);The Fund of the State Key Laboratory of Geodesy and Earth's Dynamics(No. SKLGED2015-3-2-E)

摘要: 随着GPS精密单点定位逐步由理论研究走向实际应用,越来越多的误差改正项的细节工作得到重视。就电离层延迟而言,通常使用无电离层组合消除电离层影响,但该组合仅能消除电离层一阶项延迟,而残余的二阶及高阶电离层项延迟也能达到最大厘米级量级。本文基于IGS提供的电离层TEC格网产品和IGRF12地磁模型计算电离层二阶项延迟,结合21个IGS站实测数据和全球2.5°×5°格网的模拟站点数据,研究分析电离层二阶项对PPP动态定位的结果的影响。21个IGS站实测结果显示电离层二阶项对动态PPP定位影响量级最大达到水平方向0.8 cm,高程方向达到2.4 cm,与全球模拟格网计算结果与实测计算结果影响量级基本吻合。在少数极端观测条件下,可视卫星PDOP值、电离层活跃度和地球磁场干扰均较大区域,电离层二阶项延迟接近3 cm,对定位结果的影响甚至能超过7 cm。实测数据和模拟数据均显示二阶项电离层会引起全球范围内点位坐标南向偏移的现象。由此可见,电离层二阶项延迟影响不仅能够造成点位坐标厘米量级的误差,且该影响体现一定的系统性南向偏移,无法通过平滑方法消除,因此精密单点定位需要突破厘米级的限制,应该考虑电离层二阶项延迟的影响。

关键词: 全球导航卫星系统, 电离层延迟, 电离层二阶项, 动态精密单点定位

Abstract: In the GPS precise point positioning algorithms, the ionosphere delays were considered as eliminated with ionosphere-free combination. However, the IF combination can only eliminates the first order ionosphere delays and the second order ionosphere (Ion2) delays were actually enlarged. As the Ion2 can affect the observations over centimeters level, the effects on PPP positioning results may not be negligible for centimeters-accuracy applications. In this research, the impacts of Ion2 delays on kinematic precise point positioning applications were calculated with both real and simulated observations. With 21 IGS station observations, the maximum effects of Ion2 delay on positioning result are 0.8 cm on horizontal, and over 2.4 cm on vertical. On the simulation analysis, an 2.5×5 degree global grid observations were simulated with Ion2 delay, and the maximum Ion2 delay can reach up to 3 cm and cause over 7 cm bias on positioning results. Both real and simulated results show that the Ion2 delays affect the positioning results with systematic bias on south direction, which cannot be eliminated with smoothing algorithm. Hence, it concluded that the PPP cannot be neglected the second order ionosphere delays to breakthroughs the accuracy limitation on centimeters level.

Key words: global navigation satellite system(GNSS), ionosphere delay, second order ionosphere delay, kinematic precise point positioning

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