To solve the ill-posed and accuracy problems experienced by global navigation satellite system (GNSS) computerized ionosphere tomography (CIT), this study proposes the use of the ionospheric profile data of COSMIC-2 as the initial scale factor to constrain GNSS data. At present, studies are lacking on long-term data volume statistics and accuracy assessment of COSMIC-2 ionospheric profile products. Therefore, we calculated the data volume statistics and assessed the ionospheric quality of the COSMIC-2 data for the whole year of 2020. We used incoherent scattering radar (ISR) and ionosonde data to evaluate the quality of the COSMIC-2 ionospheric profile data. To verify the accuracy and reliability of the CIT algorithm for COSMIC-2 ionosphere profile-constrained GNSS data, the American region was selected. On the plane, the tomographic results were superimposed and compared with the global ionospheric map (GIM). The root mean square (rms) of the vertical total electron content (VTEC) difference in the six periods was 0.68, 0.97, 0.63, 0.86, 0.76, and 0.82 total electron content unit (TECU), respectively. In the vertical direction, the scale factor that was not involved in the CIT was compared with the ratio of total electron contents (TECs) in each layer to the total TEC. The average difference of the ratio factors in the four periods was 3.72%, 2.79%, 1.80%, 3.05%, 1.99%, and 2.37%, respectively. Finally, an intermediate-level geomagnetic storm that occurred on July 25, 2020, was selected for analysis, and the 3-D ionospheric morphological changes and evolution characteristics of the Australian region during this geomagnetic storm were studied.

中文翻译：

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通过 GNSS 和 COSMIC-2 数据融合分析地磁暴期间电离层异常的 3-D 演化特征


针对全球导航卫星系统（GNSS）计算机电离层层析成像（CIT）存在的不适定性和精度问题，本研究提出使用COSMIC-2的电离层剖面数据作为初始比例因子来约束GNSS数据。目前，缺乏对COSMIC-2电离层剖面产品的长期数据量统计和精度评估的研究。因此，我们计算了2020年全年COSMIC-2数据的数据量统计和电离层质量评估。我们利用非相干散射雷达（ISR）和电离层探空仪数据评估了COSMIC-2电离层剖面数据的质量。为了验证 COSMIC-2 电离层剖面约束 GNSS 数据的 CIT 算法的准确性和可靠性，选择美洲地区。在平面上，将层析结果叠加并与全球电离层图（GIM）进行比较。六个周期的垂直总电子含量（VTEC）差异的均方根（rms）分别为0.68、0.97、0.63、0.86、0.76和0.82总电子含量单位（TECU）。在垂直方向上，将不涉及CIT的比例因子与每层总电子含量（TEC）与总TEC的比率进行比较。四个时期比率因子的平均差异分别为3.72%、2.79%、1.80%、3.05%、1.99%和2.37%。最后选取2020年7月25日发生的一次中级地磁暴进行分析，研究此次地磁暴期间澳大利亚地区的三维电离层形态变化和演化特征。