武汉GPS台网观测的电离层不规则结构漂移

Drifts of Ionospheric Irregularities Deduced from GPS Network Observations at Wuhan

利用2004年11月上旬强磁暴期间电离层总电子含量(QTEC)和电波闪烁武汉GPS监测台网的观测数据,采用小波去噪和互相关技术,计算了电离层不规则结构的视在纬圈漂移速度.结果表明,在11月10日夜间,各种尺度不规则结构的存在使L-波段闪烁活动与QTEC起伏均显著增强,振幅闪烁指数(S4)最大达到1.0.根据观测台网实测的QTEC变化率(RT),得到引起闪烁和QTEC起伏的不规则结构沿纬圈向西漂移,漂移速度从午夜前(21:30BST)的约130 m/s下降到午夜后(02:30 BST)的40 m/s左右.该研究为电离层不规则结构纬向漂移速度的测量提供了一种可行的方法.

The amplitude scintillations and QTEC were measured using three GPS ionospheric scintillation and QTEC monitors at Wuhan. By using wavelet analysis and cross-correlation technique, the zonal apparent drift velocity of the ionospheric irregularities was estimated based on the observations of the three spaced GPS receivers during the great storm occurring in Nov. 2004. Results show that there were the different scale ionospheric irregularities which caused strong amplitude scintillations and QTEC rapid fluctuations in the night of Nov. 10. From measurements of the rate of QTEC（RT） at three spaced receivers, it is found that the irregularities drifted westward along the zonal direction, and the drift velocities exhibited degressive trend, changing from about 130 m/s at 21：30 BST to about 40 m/s at 02：30 BST. This research will provide a feasible method for measurement of the ionospheric zonal velocity.