中文摘要：

利用澳大利亚科廷大学双频北斗GEO数据,分析了2013、2014年该地电离层VTEC的日变化、季节变化特性。在此基础上,针对Klobuchar模型在计算穿刺点VTEC上存在的不足提出一种改进模型。最后利用1a的数据对改进模型计算VTEC的精度进行评估。结果表明,改进模型计算VTEC的精度明显高于原模型,绝大部分月份精度提高超过10%,总体精度达到64%以上。

英文摘要：

This paper provides a detailed analysis of the ionosphere using GEO satellites of China＇s Beidou navigation satellite system. Taking Cnrtin University Beidou continuous observation station＇s data as an example, the paper extensively analyzes the ionospheric TEC variations in a sample day in equinox, summer and winter, as well as seasonal variations in 2013 and 2014. In addition, based on the temporal variations in TEC, the paper improves the Klobuchar ionospheric model broadcast by GPS satellites. Finally, the effect of the improved model is validated using a year＇s data. The paper shows that the accuracy of the new Klobuehar model is obviously superior to the former model. The precision of the new model increases more than 10~ in most months, and it reaches over 64% in com- puting the ionosphere vertical TEC.