基于相似变换法的CGCS2000骨架网精化

利用GAMIT/GLOBK软件，分别采用相似变换法和强约束法对扩展后的260个CGCS2000骨架网点的GNSS观测数据进行处理。按照3种方案进行平差获得站点在ITRF2008框架下的坐标，结果得出，使用强约束法时，起算数据的约束不同会引起定位结果的差异，不恰当的约束会造成精度的降低；相似变换法可以避免不恰当的约束引起的网的变形和扭曲，且可靠性更高，其平均中误差优于1 mm。

The Refining of the Skeleton of CGCS2000 Based on Similarity Transformation Method

In this paper, the similarity transformation method and the strong constraint method are used in processing the extended 260 CGCS2000 skeleton points with the GAMIT/GLOBK software. Coordinates of stations in the ITRF2008 are obtained through adjustment calculation adopting three schemes. The comparison result of the three schemes shows that different constraints on the original data will result in different positioning precision, and that inappropriate constraints may lead to network deformation and distortion with the strong constraint method. The similarity transformation method is more reliable and can avoid the above-mentioned problems. Its average mean square error is less than 1 mm.