中国地区不同区域电离层时空频域特性分析

利用中国区域电离层格网数据，采用频谱分析方法研究中国不同区域的电离层周期差异和极值差异，并采用电离层梯度计算法分析不同区域的电离层小尺度时空变化特性。结果表明：1）相比北方区域，南方区域电离层周期性特征更为明显；2）经度变化为5°时，全国范围内的电离层TEC变化值大多在-10~10 TECu之间；纬度变化为2.5°时，全国范围内的电离层TEC变化值大多在-20~20 TECu之间，南北部空间变化特性差异较大，东西部差异较小；3）时间间隔为1 h时，全国范围内的电离层TEC变化值大多在5~25 TECu之间，南北方时间变化特性差异较大，东西部差异较小，但随着时间间隔增大，东西部时间变化特性差异逐渐明显。研究结论可为中国区域的实时电离层建模工作提供理论参考，同时对中国区域的电离层时空变化、电离层磁暴监测研究有一定参考意义。

Analysis of Ionospheric Characteristics of Time-Space-Frequency Domains in Different Regions of China

Using the regional ionospheric grid data and spectral analysis method, we study the ionospheric period difference and extreme value difference in different regions of China. Moreover, using the ionospheric gradient calculation method, we analyze the small-scale spatiotemporal variation characteristics of ionosphere in different regions. The results show that compared with the northern region, the ionospheric periodicity is more obvious in the southern region. When the longitude changes by 5°, most of the TEC changes are between -10 and 10 TECu. When latitude changes by 2.5°, the TEC varies from -20 to 20 TECu, and there is a great difference between the north and south region, but little difference between the east and west. When the time interval is 1 hour, most ionospheric TEC changes in China are between 5 and 25 TECu, and there is a great difference in the time variation characteristics between the north and south region, but little difference between the east and west. However, with the increase of the time interval, the difference in the time variation characteristics between the east and west is gradually more obvious. The conclusions can provide theoretical reference for real-time ionospheric modeling in China and have certain referential significance for ionospheric spatiotemporal changes and ionospheric magnetic storm monitoring in China.