Application of Robust Estimation Methods to Displacements Determination in Geodetic Control Network of Dam

The paper presents results of research designed to estimate the usefulness and efficiency of robust estimation methods in points' displacements determination in the geodetic control of earth dam. The method of Huber, Hampel, danish and linear were tested. The horizontal control network consists of 7 points what gave 32 distance and 25 angle observations. Author carried out two surveying campaigns. The way of preparing intentionally contaminated with outliers sets of observations used in numerical tests were presented. Affected sets were adjusted using least squares and robust estimation. The study presents among others average coordinates differences between least squares adjustment and four robust estimation methods and average standard deviations. There is also shown the effect of points' stability evaluation and estimated displacements after least squares and robust adjustment. The paper shows the advantage of M-estimation to reduce the influence of outliers on estimated network parameters over the ordinary least squares adjustment.