利用GPS双频观测数据分析了仪器偏差对计算电离层TEC的影响,结果表明忽略仪器偏差的影响不能正确反映测站上空电离层总电子含量的变化规律。验证了短期内仪器偏差的稳定性,并在此基础上研究了2005年太阳活动低峰年区域电离层VTEC的周年变化规律,揭示了电离层VTEC半年变化、季节性变化及冬季异常等现象。
The effect of instrument bias (IB) on calculating ionospheric total electron content (TEC) was analyzed by using GPS dual-frequency measurement. The result indicated that it could reflect the state of the ionosphere better when the instrumental bias was ruled out. The validation was applied to the short-term stability of IB. The variation law of regional ionospheric vertical total electron content (VTEC) was investigated during the minimum solar activity, such as semi-year and seasonal variations, and winter anomaly of ionosphere.