Space weather phenomena such as scintillations of Global Navigation Satellite Systems (GNSS) signals are of increasing importance for aviation, the maritime, and civil engineering industries. The ionospheric plasma irregularities causing scintillations are associated with strong gradients in ionospheric plasma density. To provide nowcasts and forecasts of space weather effects, it is vital to monitor the ionosphere and detect strong density variations. To reconstruct plasma density variations in the polar cap ionosphere, we use total electron content (TEC) estimates from the Swarm satellites' GPS receivers. By considering events where the Swarm satellites are in close proximity, we obtain plasma density variations by inverting TEC measurements on a two‐dimensional grid. We first demonstrate the method using synthetic test data, before applying it to real data. The method is validated using in situ Langmuir probe measurements and ground‐based TEC observations. We find that the new method can reproduce density variations, although it is sensitive to the geometry of the Swarm satellite constellation and to the calculated plasma temperature. Our proposed method opens new possibilities for ionospheric plasma monitoring that uses GPS receivers aboard low Earth orbit (LEO) satellites.

中文翻译：

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群体电离层等离子体密度变化的二维重建

诸如全球导航卫星系统（GNSS）信号闪烁之类的空间天气现象对于航空，海事和土木工程行业越来越重要。引起闪烁的电离层等离子体不规则性与电离层等离子体密度的强梯度有关。为了提供太空天气影响的临近预报和预报，至关重要的是监测电离层并检测强密度变化。为了重建极地帽电离层中的等离子体密度变化，我们使用了Swarm卫星的GPS接收器中的总电子含量（TEC）估算值。通过考虑Swarm卫星非常靠近的事件，我们可以通过反转二维网格上的TEC测量来获得等离子体密度的变化。我们首先使用综合测试数据演示该方法，在将其应用于实际数据之前。该方法通过使用原位Langmuir探针测量和地面TEC观测得到验证。我们发现，新方法可以重现密度变化，尽管它对Swarm卫星星座的几何形状和计算出的等离子体温度很敏感。我们提出的方法为电离层等离子体监测打开了新的可能性，该方法使用低地球轨道（LEO）卫星上的GPS接收器。