GEO卫星区域电离层监测分析

Monitoring and Analysis of Regional Ionosphere with GEO Satellite Observations

由于GEO卫星的静地特性,由双频观测数据获取的穿刺点垂直总电子含量(VTEC)可以充分反映电离层的时域变化,而根据地面监测站的分布,可以进一步获取VTEC的空域变化。分析根据区域卫星导航系统观测数据计算VTEC的精度,理论分析表明VTEC精度优于2 TECU。根据实测数据计算分析我国高、中、低纬度不同穿刺点电离层平时、磁暴期间的周日变化特性和2011年全年变化特性,并与IGS全球电离层图(GIM)的穿刺点插值结果进行分析比较。结果表明,两者在电离层周日和全年变化趋势上具有很好的一致性,但磁暴期间我国低纬度地区GIM误差的峰值可达29TECU,2011年全年评估结果 GIM误差标准差为2～8 TECU。根据2011年的观测结果,电离层VTEC呈现出明显的半年异常现象。区域卫星导航系统为我国的电离层监测尤其是空间天气期间的电离层监测提供了新的支持。

Due to the geostationary feature of GEO satellites,the vertical total electron content（VTEC） at ionosphere piece point（IPP） obtained from GEO dual-frequency observations can fully reflect the temporal variety of ionosphere,and the VTEC spatial variety can be further obtained from the distribution of ground stations.The accuracy of measured VTEC from Compass observations is firstly analyzed,and theoretical analysis indicates the accuracy is better than 2 TECU.The daily and seasonal VTEC changes of different ionosphere piece points in different latitude regions are given by use of observations of Compass navigation system.Note that the VTEC changes during geomagnetic storm are also elaborated.In contrast,the interpolation results of the global ionosphere map（GIM） are given,which are provided by IGS.Analysis shows that there is considerable consistency between the trends of these two ionosphere results,but the peak discrepancy during geomagnetic storm in the low latitudes of China can be up to 29 TECU,and the standard deviation of VTEC of 2011 is 2~8 TECU.Measurement data ensure higher resolution and confidence on regional ionosphere monitoring.According to the observations of 2011,the ionosphere VTEC variety shows a significant semiannual anomaly phenomenon.Compass navigation system provides a new support for the monitoring of regional ionosphere,especially for the study of ionosphere response for space weather.