Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the Antarctic
Global navigation satellite system (GNSS) can provide dual-frequency observation data, which can be used to effectively calculate total electron content (TEC). Numerical studies have utilized GNSS-derived TEC to evaluate the accuracy of ionospheric empirical models, such as the International Referen...
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MDPI AG
2021-02-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/21/4/1551 |
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| author | Zihuai Guo Yibin Yao Jian Kong Gang Chen Chen Zhou Qi Zhang Lulu Shan Chen Liu |
| author_facet | Zihuai Guo Yibin Yao Jian Kong Gang Chen Chen Zhou Qi Zhang Lulu Shan Chen Liu |
| author_sort | Zihuai Guo |
| collection | DOAJ |
| description | Global navigation satellite system (GNSS) can provide dual-frequency observation data, which can be used to effectively calculate total electron content (TEC). Numerical studies have utilized GNSS-derived TEC to evaluate the accuracy of ionospheric empirical models, such as the International Reference Ionosphere model (IRI) and the NeQuick model. However, most studies have evaluated vertical TEC rather than slant TEC (STEC), which resulted in the introduction of projection error. Furthermore, since there are few GNSS observation stations available in the Antarctic region and most are concentrated in the Antarctic continent edge, it is difficult to evaluate modeling accuracy within the entire Antarctic range. Considering these problems, in this study, GNSS STEC was calculated using dual-frequency observation data from stations that almost covered the Antarctic continent. By comparison with GNSS STEC, the accuracy of IRI-2016 and NeQuick2 at different latitudes and different solar radiation was evaluated during 2016–2017. The numerical results showed the following. (1) Both IRI-2016 and NeQuick2 underestimated the STEC. Since IRI-2016 utilizes new models to represent the F2-peak height (hmF2) directly, the IRI-2016 STEC is closer to GNSS STEC than NeQuick2. This conclusion was also confirmed by the Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) occultation data. (2) The differences in STEC of the two models are both normally distributed, and the NeQuick2 STEC is systematically biased as solar radiation increases. (3) The root mean square error (RMSE) of the IRI-2016 STEC is smaller than that of the NeQuick2 model, and the RMSE of the two modeling STEC increases with solar radiation intensity. Since IRI-2016 relies on new hmF2 models, it is more stable than NeQuick2. |
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| language | English |
| last_indexed | 2024-03-09T00:36:34Z |
| publishDate | 2021-02-01 |
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| series | Sensors |
| spelling | doaj.art-7edf92bdfcc5477cb814a29b4d8d7d5e2023-12-11T18:08:30ZengMDPI AGSensors1424-82202021-02-01214155110.3390/s21041551Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the AntarcticZihuai Guo0Yibin Yao1Jian Kong2Gang Chen3Chen Zhou4Qi Zhang5Lulu Shan6Chen Liu7School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, ChinaSchool of Geodesy and Geomatics, Wuhan University, Wuhan 430079, ChinaChinese Antarctic Center of Surveying and Mapping, Wuhan 430079, ChinaCollege of Marine Science and Technology, China University of Geosciences, Wuhan 430074, ChinaSchool of Electronic Information, Wuhan University, Wuhan 430072, ChinaSchool of Geodesy and Geomatics, Wuhan University, Wuhan 430079, ChinaSchool of Geodesy and Geomatics, Wuhan University, Wuhan 430079, ChinaSchool of Geodesy and Geomatics, Wuhan University, Wuhan 430079, ChinaGlobal navigation satellite system (GNSS) can provide dual-frequency observation data, which can be used to effectively calculate total electron content (TEC). Numerical studies have utilized GNSS-derived TEC to evaluate the accuracy of ionospheric empirical models, such as the International Reference Ionosphere model (IRI) and the NeQuick model. However, most studies have evaluated vertical TEC rather than slant TEC (STEC), which resulted in the introduction of projection error. Furthermore, since there are few GNSS observation stations available in the Antarctic region and most are concentrated in the Antarctic continent edge, it is difficult to evaluate modeling accuracy within the entire Antarctic range. Considering these problems, in this study, GNSS STEC was calculated using dual-frequency observation data from stations that almost covered the Antarctic continent. By comparison with GNSS STEC, the accuracy of IRI-2016 and NeQuick2 at different latitudes and different solar radiation was evaluated during 2016–2017. The numerical results showed the following. (1) Both IRI-2016 and NeQuick2 underestimated the STEC. Since IRI-2016 utilizes new models to represent the F2-peak height (hmF2) directly, the IRI-2016 STEC is closer to GNSS STEC than NeQuick2. This conclusion was also confirmed by the Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) occultation data. (2) The differences in STEC of the two models are both normally distributed, and the NeQuick2 STEC is systematically biased as solar radiation increases. (3) The root mean square error (RMSE) of the IRI-2016 STEC is smaller than that of the NeQuick2 model, and the RMSE of the two modeling STEC increases with solar radiation intensity. Since IRI-2016 relies on new hmF2 models, it is more stable than NeQuick2.https://www.mdpi.com/1424-8220/21/4/1551International Reference Ionosphere modelNeQuick modelAntarcticGNSS STECaccuracy analysis |
| spellingShingle | Zihuai Guo Yibin Yao Jian Kong Gang Chen Chen Zhou Qi Zhang Lulu Shan Chen Liu Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the Antarctic Sensors International Reference Ionosphere model NeQuick model Antarctic GNSS STEC accuracy analysis |
| title | Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the Antarctic |
| title_full | Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the Antarctic |
| title_fullStr | Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the Antarctic |
| title_full_unstemmed | Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the Antarctic |
| title_short | Accuracy Analysis of International Reference Ionosphere 2016 and NeQuick2 in the Antarctic |
| title_sort | accuracy analysis of international reference ionosphere 2016 and nequick2 in the antarctic |
| topic | International Reference Ionosphere model NeQuick model Antarctic GNSS STEC accuracy analysis |
| url | https://www.mdpi.com/1424-8220/21/4/1551 |
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