Assessment and Comparison of Broadcast Ionospheric Models: NTCM-BC, BDGIM, and Klobuchar
Assessment and Comparison of Broadcast Ionospheric Models: NTCM-BC, BDGIM, and Klobuchar
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广播电离层模型的评估和比较：NTCM-BC、BDGIM 和 Klobuchar
DOI：
10.3390/rs12071215
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发表时间：
2020-04-01
期刊：
影响因子：
5
通讯作者：
Lv, Yifei
中科院分区：
文献类型：
--
作者：
Yang, Chao;Guo, Jing;Lv, Yifei
对于单频全球导航卫星系统（GNSS）用户，电离层延迟是影响定位精度的主要误差源。应用广播电离层改正模型来消除电离层延迟对于米到分米级精度的定位是必不可少的。为了支持实时单频操作，特别是在中国地区，我们评估了三个广播电离层校正模型的性能，即诺伊斯特雷利茨总电子含量（TEC）广播模型（NTCM-BC），北斗全球广播电离层延迟校正模型（BDGIM）和Klobuchar模型。在这项研究中，Klobuchar和BDGIM的广播系数直接从导航数据文件中获得。估算了中国和全球区域的两组NTCM-BC系数。来自80多个验证站的倾斜总电子含量（STEC）数据和欧洲轨道确定中心（CODE）的最终垂直TEC（VTEC）数据被用作独立的基准进行比较。与2019年DOY 101和DOY 199期间的GPS STEC相比，NTCM-BC、BDGIM和Klobuchar的电离层校正率在中国分别为79.4%、64.9%和57.7%。对于全球区域，这三个模型的均方根（RMS）误差分别为3.67 TECU（1 TECU = 10（16）电子/m（2）），5.48 TECU和8.92 TECU。与同期CODE VTEC相比，NTCM-BC、BDGIM和Klobuchar分别可以校正72.6%、69.8%和61.7%的电离层延迟。因此，建议将NTCM-BC用作新一代北斗卫星导航系统（BDS）及其星基增强系统的广播电离层模型。
For single-frequency Global Navigation Satellite Systems (GNSSs) users, ionospheric delay is the main error source affecting the accuracy of positioning. Applying a broadcast ionospheric correction model to mitigate the ionospheric delay is essential for meter-to-decimeter-level accuracy positioning. To provide support for real-time single-frequency operations, particularly in the China area, we assessed the performance of three broadcast ionospheric correction models, namely, the Neustrelitz total electron content (TEC) broadcast model (NTCM-BC), the BeiDou global broadcast ionospheric delay correction model (BDGIM), and the Klobuchar model. In this study, the broadcast coefficients of Klobuchar and BDGIM are obtained from the navigation data files directly. Two sets of coefficients of NTCM-BC for China and global areas are estimated. The slant total electron contents (STEC) data from more than 80 validation stations and the final vertical TEC (VTEC) data of the Center for Orbit Determination in Europe (CODE) are used as independent benchmarks for comparison. Compared to GPS STEC during the period of Day of Year (DOY) 101 similar to 199, 2019, the ionospheric correction ratio of NTCM-BC, BDGIM, and Klobuchar are 79.4%, 64.9%, and 57.7% in China, respectively. For the global area, the root-mean-square (RMS) errors of these three models are 3.67 TECU (1 TECU = 10(16) electrons/m(2)), 5.48 TECU, and 8.92 TECU, respectively. Compared to CODE VTEC in the same period, NTCM-BC, BDGIM, and Klobuchar can correct 72.6%, 69.8%, and 61.7% of ionospheric delay, respectively. Hence, NTCM-BC is recommended for use as the broadcast ionospheric model for the new-generation BeiDou satellite navigation system (BDS) and its satellite-based augmentation system.