Study and application of the analytical method for initial data compatibility of GPS control network

The reference points of different class or different areas may exist errors.If these reference points which include errors were used as points of initial points,the result must influence the GPS precision especially when the reference points include gross error.In this paper the initial data compatibility of GPS control network was analyzed using direct analytic method of adjustment result,the comparison method of actual baseline,the unit weight variance hypothesis testing method and annexed traverse coordinate misclosure testing method,and eliminated known points including gross error to ensure survey precision and the reliability.