In comparison of the results of Klobuchar and VTEC in the same period of time, the precision of VTEC is much better than Klobuchar and the improving methods of VTEC is advanced.

• 使用同一时段的观测数据,将克罗布歇模型和单站VTEC模型的结果进行了比较,发现用GPS双频观测值建立的单站VTEC模型的精度明显优于广播星历中的克罗布歇模型,并提出了进一步提高单站VTEC模型精度的方法。