Determination of Point Displacements in the Geodetic Network

Abstract

This paper describes the procedure for testing the statistical significance of point displacements in the geodetic network as the intermediate stage between the adjustment of respective epochs measurements and an in-depth deformation analysis. The cumulative distribution function of the test statistic, presenting the relation between the displacement and the displacement accuracy, is determined by simulations. On the basis of this cumulative distribution function a critical value of the test statistic for a selected significance level is determined. In the null hypothesis it is assumed that the point is stable. A comparison of the critical value to the test statistic value is made and the actual risk level for rejecting the null hypothesis is estimated. Further on, a practical example of implementing the test in a simulated network is given. The test statistic proved to be simple and applicable: The points with significant displacements were identified successfully.