An EISCAT UHF/ESR Experiment That Explains How Ionospheric Irregularities Induce GPS Phase Fluctuations at Auroral and Polar Latitudes
An EISCAT UHF/ESR Experiment That Explains How Ionospheric Irregularities Induce GPS Phase Fluctuations at Auroral and Polar Latitudes
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DOI：
10.1029/2020rs007236
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发表时间：
2021-08
期刊：
影响因子：
1.6
通讯作者：
H. M. John;B. Forte;I. Astin;T. Allbrook;A. Arnold;B. Vani;I. Häggström;H. Sato
中科院分区：
文献类型：
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作者：
H. M. John;B. Forte;I. Astin;T. Allbrook;A. Arnold;B. Vani;I. Häggström;H. Sato
电离层等离子体密度的不规则性限制了使用全球导航卫星系统（GNSS）提供精确和实时服务。进行了 EISCAT UHF/ESR 实验，以表征电子密度不规则性对高纬度电离层中与 GPS 射线路径横向的 TEC 时间波动的影响。描述了两个代表性案例研究：(a) 极光粒子降水后的极光电离层和 (b) 极地斑块漂移以及粒子降水后的极地电离层中产生的时间 TEC 波动的增强。结果表明，TEC波动增强的根源是通过大到中尺度的不规则性（即从E区的几公里到F区的几十公里）传播，并且发生在E区约400km和F区约800km的空间距离上，且呈斑片状分布。此外，结果表明，极性等离子体斑块和粒子降水产生的 TEC 波动增强发生在相似的时间尺度上，从而解释了高纬度电离层中较高相位闪烁指数的整体观测。在颗粒降水和等离子体斑块同时存在的情况下，TEC 波动增强的时间尺度上的相似性表明，通过地面 GNSS 观测来监测和跟踪等离子体斑块存在固有的局限性。
A limitation to the use of Global Navigation Satellite System (GNSS) for precise and real‐time services is introduced by irregularities in the ionospheric plasma density. An EISCAT UHF/ESR experiment was conducted to characterize the effect of electron density irregularities on temporal fluctuations in TEC along directions transverse to GPS ray paths in the high latitudes ionosphere. Two representative case studies are described: Enhancements in temporal TEC fluctuations originating (a) in the auroral ionosphere following auroral particle precipitation and (b) in the polar ionosphere following the drift of a polar patch as well as particle precipitation. The results indicate that the origin of enhancements in TEC fluctuations is due to the propagation through large‐to‐medium scale irregularities (i.e., ranging from few kilometres in the E region to few tens of kilometres in the F region) and occurring over spatial distances of up to approximately 400km in the E region and up to approximately 800km in the F region with a patchy distribution. Furthermore, the results indicate that enhancements in TEC fluctuations produced by polar plasma patches and particle precipitation occur over similar temporal scales, thus explaining the overall observation of higher phase scintillation indices in the high‐latitude ionosphere. The similarity in the temporal scales over which enhancements in TEC fluctuations occur in the presence of both particle precipitation and plasma patches suggests an intrinsic limitation in the monitoring and tracking of plasma patches through ground GNSS observations.