空间环境因素对西北地区电离层空间特征影响

Influence of space environment factors on ionospheric spatial characteristics in northwest China

针对电离层延迟对导航定位带来的影响,而空间环境因素是影响电离层总电子含量(TEC)的重要因素之一。基于中国大陆构造环境监测网络(CMONOC)全球卫星导航系统(GNSS)观测数据,计算西北地区垂直总电子含量(VTEC),将VTEC值分别与太阳活动指数与地磁活动指数进行线性回归分析,结果表明:西北地区电离层VTEC的月均值与太阳射电通量F10.7的相关性均达到了强度相关;在地磁活跃时期,西北地区VTEC的月均值与地磁指数Dst的相关性达到了中度相关,证实了太阳活动、地磁活动是影响电离层活跃度的重要影响因素之一。通过对西北地区经纬度变化特征分析,结果表明:不同纬度电离层VTEC值变化趋势完全相同,在同一刻时间,随着纬度的增加,电离层VTEC值呈减小趋势,而经度无明显特征变化。

Aiming at the influence of ionospheric delay on navigation and positioning, space environmental factors are one of the important factors that affect the ionospheric Total Electron Content(TEC). Based on Crustal Movement Observation Network of China(CMONOC) Global Navigation Satellite System(GNSS) observation data, the Vertical Total Electron Content(VTEC) in northwest China is calculated. The results show that the correlation between monthly mean value of ionospheric VTEC and solar radio flux F10.7 in northwest China has reached intensity correlation;during the period of geomagnetic activity, the monthly mean value of VTEC in northwest China is moderately correlated with the geomagnetic index Dst, which proves that solar activity and magnetic activity are one of the important factors affecting the ionospheric activity. Through the analysis of latitude and longitude variation characteristics in northwest China, the results show that the variation trend of ionospheric VTEC values in different latitudes is exactly the same. At the same moment, with the increase of latitude, the ionospheric VTEC values show a decreasing trend, while the longitude has no obvious characteristic change.