测绘学报 ›› 2014, Vol. 43 ›› Issue (11): 1151-1157.doi: 10.13485/j.cnki.11-2089.2014.0176

• 学术论文 • 上一篇    下一篇

不同Klobuchar模型参数的性能比较

王斐1,2,吴晓莉1,3,周田1,李宇翔1   

  1. 1. 北京卫星导航中心
    2. 清华大学
    3. 北京环球信息应用开发中心
  • 收稿日期:2013-12-05 修回日期:2014-03-20 出版日期:2014-11-20 发布日期:2014-12-02
  • 通讯作者: 王斐 E-mail:wakenforest@126.com
  • 基金资助:

    国家自然科学青年基金;国家高技术研究发展计划;第三届中国卫星导航学术年会青年优秀论文资助课题

Performance Comparison between Different Klobuchar Model Parameters

WANG Fei1,2,4,WU Xiaoli1,3,4,LI Yuxiang1,4, 1,4   

  1. 1. Beijing Navigation Center
    2. Tsinghua University
    3.
    4. Beijing navigation center
  • Received:2013-12-05 Revised:2014-03-20 Online:2014-11-20 Published:2014-12-02
  • Contact: WANG Fei E-mail:wakenforest@126.com
  • Supported by:

    ;National High Technology Research and Development Program of China

摘要:

对于GPS单频用户而言,电离层延迟是最重要的误差来源之一。GPS系统使用Klobuchar模型对电离层延迟进行改正,其改正数从370组常数中选取。目前全球分布的GPS测站可以获得高精度的全球电离层监测结果,GPS为什么不发播采用实测数据计算得到的Klobuchar模型参数呢?本文针对这一问题进行分析。首先对欧洲定轨中心CODE提供的全球电离层图GIM预报COPG电离层进行精度评估,然后根据COPG电离层进行Klobuchar模型参数拟合并利用IGS提供的事后高精度电离层图进行精度分析,最后将不同的电离层模型参数应用于单点定位以评估其对单频用户的影响。分析结果表明:受8参数的Klobuchar模型本身结构限制,采用全球实测数据计算的电离层模型参数与导航电文中发播的电离层模型精度相当,为55%左右。而仅采用地磁纬度45oS以北的数据拟合得到的模型参数,其电离层改正精度有明显提升,可达65%左右,但其对单频用户定位精度改善不明显。本文研究结果为我国全球电离层建模提供参考。

关键词: Klobuchar模型, GPS, 电离层延迟, 全球电离层图

Abstract:

To GPS single-frequency user, the ionospheric delay is one of the most important sources of errors. GPS uses Klobuchar model to correct the ionospheric delay whose corrections come from 370 groups of constants derived from empirical models and historical data. Currently stations distributed all over the world can provide ionosphere monitoring results with high precision, why GPS doesn’t broadcast Klobuchar model parameters calculated with observed data? This article focuses on this question. Firstly estimating the precision of predicted global ionosphere maps, COPG, provided by Center for Orbit Determination in Europe (CODE). Secondly we fit the Klobuchar model parameters with COPG. Then we assess the parameters’ precision with global ionosphere maps provided by IGS. Finally we do single point positioning using different Klobuchar parameters to evaluate their influences on GPS single-frequency users. Results show that restricted by Klobuchar model with 8 parameters, precision of parameters fitted using global observed data is just equal with GPS broadcast parameters, both around 55%. On the other hand, precision of model parameters fitted using data on the north of geomagnetic latitude 45oS is much higher, which arrives about 65%, but it performs no better in positioning of single-frequency users. Results in this article provide reference to ionosphere modeling of our nation.

Key words: Klobuchar model, GPS, ionosphere delay, GIM

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