A Rigorous and User-Friendly Algorithm for Global Congruency Test in Geodetic Deformation Analysis

Identification of stable reference points is the most critical stage in deformation analysis of geodetic control networks. Today, two basically different approaches have been developed to this task: a global congruency test which employs least squares estimation and a robust approach which employs robust M-estimation. The global congruency test is more widely accepted. However, a rigorous algorithm of global congruency test is not easy to use and its simplified form is often used in practice. Of course, such simplified algorithm is not rigorous and does not give optimal results. This paper presents a rigorous and, at the same time, a user-friendly algorithm. The idea behind this algorithm comes from the theory of generalized likelihood ratio testing which is today widely used in mathematical statistics. The rigorousness of the presented algorithm was proved on a simple simulated geodetic network.