Evaluation of Ionospheric Delay Effects on Multi-GNSS Positioning Performance
Evaluation of Ionospheric Delay Effects on Multi-GNSS Positioning Performance
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DOI：
10.3390/rs11020171
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发表时间：
2019-01-01
期刊：
影响因子：
5
通讯作者：
Hoque, M. M.
中科院分区：
文献类型：
--
作者：
Su, Ke;Jin, Shuanggen;Hoque, M. M.
电离层延迟是多GNSS定位的重要误差源。我们提出了不同的处理策略，以充分利用电离层延迟对多频和多GNSS定位性能的影响，包括标准点定位（SPP）和精确点定位（PPP）的情况。利用多GNSS实验（MGEX）台站提供的连续30天从10个台站收集的数据集，对四星座信号进行单频SPP/PPP和双频PPP测试。实验结果表明，对于单频SPP，全球电离层地图（GIMs）改正的精度最高，在E和U分量，诺伊斯特雷利茨TEC模型（NTCM）解的精度优于广播电离层模型（BIM）。通过观测组合消除电离层参数相当于PPP中参数的估计。与单频非组合（UC）方法相比，PPP与外部电离层模型的平均收敛时间缩短。BIM、NTCM和GIM约束的四星座L2单频PPP的改善分别为15.2%、24.8%和28.6%。采用电离层模型的双频PPP在收敛时间方面的改进对于不同的星座是不同的，而仅采用全球轨道导航卫星系统的解决方案的改进最小。与UC解决方案相比，BIM、NTCM和GIM约束的四星座L1/L2双频PPP的收敛时间分别提高了5.2%、6.2%和8.5%。有电离层约束的PPP定位精度略好，而有GIM约束的PPP定位精度最好。多GNSS的组合可以有效地提高定位性能。
Ionospheric delay is a significant error source in multi-GNSS positioning. We present different processing strategies to fully exploit the ionospheric delay effects on multi-frequency and multi-GNSS positioning performance, including standard point positioning (SPP) and precise point positioning (PPP) scenarios. Datasets collected from 10 stations over thirty consecutive days provided by multi-GNSS experiment (MGEX) stations were used for single-frequency SPP/PPP and dual-frequency PPP tests with quad-constellation signals. The experimental results show that for single-frequency SPP, the Global Ionosphere Maps (GIMs) correction achieves the best accuracy, and the accuracy of the Neustrelitz TECmodel (NTCM) solution is better than that of the broadcast ionospheric model (BIM) in the E and U components. Eliminating ionospheric parameters by observation combination is equivalent to estimating the parameters in PPP. Compared with the single-frequency uncombined (UC) approach, the average convergence time of PPP with the external ionospheric models is reduced. The improvement in BIM-, NTCM- and GIM-constrained quad-constellation L2 single-frequency PPP was 15.2%, 24.8% and 28.6%, respectively. The improvement in convergence time of dual-frequency PPP with ionospheric models was different for different constellations and the GLONASS-only solution showed the least improvement. The improvement in the convergence time of BIM-, NTCM- and GIM-constrained quad-constellation L1/L2 dual-frequency PPP was 5.2%, 6.2% and 8.5%, respectively, compared with the UC solution. The positioning accuracy of PPP is slightly better with the ionosphere constraint and the performance of the GIM-constrained PPP is the best. The combination of multi-GNSS can effectively improve the positioning performance.