利用GPS监测电离层总电子含量的季节性变化

Monitoring Seasonal Variations of Ionospheric TEC Using GPS Measurements

利用Georgiadiou电离层模型计算了GPS系统硬件延迟,从而由双频伪距观测值获取绝对电离层总电子含量值。利用北京IGS站的GPS观测数据分别计算了2000年和2004年各个不同月份的总电子含量值,对两年各月份的总电子含量进行多项式拟合,发现总电子含量的季节性变化趋势一致。

Georgiadiou ionospheric model was adopted to determine satellite-plus-receiver differential delay. The satellite-plus-receiver differential delay was estimated as constant values for each day. Dual-frequency GPS pseudo-ranges observables were used to compute vertical TEC（VTEC）. All the monthly mean VTEC profiles were presented using GPS data of Beijing IGS site between 2000 and 2004. All the monthly averaged values and amplitudes of VTEC were also presented. The results indicate that the VTEC has seasonal dependency. The maximum VTEC values are observed in March and April, the minimum VTEC values in December. The seasonal variations trend is found to be the same after polynomial fitting be tween 2000 and 2004.