小区域GPS形变监测网GAMIT数据处理结果与IGS站选取的关系探讨

The study of the relationship between the result of GAMIT processing and the choice of IGS station in small GPS deformation monitoring net

利用GAMIT软件对北京市GPS形变监测网的2004年6月6日到6月12日的数据进行了处理,在处理过程中,对IGS站的选取分了4种情况:①选取13个IGS站;②选取10个IGS站;③选取6个IGS站;④选取1个IGS站。并对4种情况得出的结果从基线重复率WRMS、基线分量的偏差、标准化均方根差NRMS进行了比较,得出以下结论:对于100km内的小区域GPS形变监测网,使用GAMIT软件处理GPS观测数据,最好选取IGS站为区域网提供参考框架;同时对小区域的GPS形变监测网选取6个IGS站就比较合适,解算结果的精度可以达到监测地壳形变的要求;IGS站并不是数量上一定要多,但空间分布要尽量均匀,测站的近似坐标尽量准确。

The observation data from GPS deformation monitoring net of Earthquake Administration of Beijing Municipality has been processed using GAMIT software. In the processing, the choice of IGS station were divided into four cases： ①Choosing 13 IGS station;②Choosing 10 IGS station; ③Choosing 6 IGS station; ④Choosing 1 IGS Station. The results of the four cases were compared from the repeat rate of baseline, baseline each vector offset and the normalized root mean square （NRMS）. The conclusions is that it would be better choosing the reference frame offered by IGS for small GPS deformation net when processing GPS data with GAMIT software. For small GPS deformation monitoring net about 100 km, the best number choice of IGS station is 6. The quantity of IGS might not be the most, but the chosen IGS stations should be well distributed in space as possible as they could. And the approximate coordinates of observation station should be accurate as possible as they could.