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 in the E region and up to approximately 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.

中文翻译：

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EISCAT UHF/ESR 实验解释了电离层不规则性如何在极光和极地纬度引起 GPS 相位波动

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 TEC 沿横向于高纬度电离层中 GPS 射线路径的方向的时间波动的影响。描述了两个具有代表性的案例研究：源自 (a) 极光粒子降水之后的极光电离层和 (b) 极地斑块漂移和粒子降水之后的极地电离层中的时间 TEC 波动的增强。结果表明 TEC 波动增强的起源是由于通过大到中等规模的不规则传播（即，在 E 区和大约在 F 区，分布不均。此外，结果表明极地等离子体斑块和粒子沉淀产生的 TEC 波动的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总体观察结果。在粒子沉淀和等离子体斑块存在的情况下，TEC 波动增强的时间尺度的相似性表明，通过地面 GNSS 观测监测和跟踪等离子体斑块存在内在限制。