BLUNDER DETECTION TECHNIQUES IN ADJUSTMENT COMPUTATIONS

Abstract

In adjustment of geodetic and photogrammetric networks, the surveying engineer faces many problems, such as errors of blunder nature in the observations (when comparing the homogeny of precision) make these observations odd from the result, and effecting directly on observation values after adjustment, and the statistical results after analysis as, adjusted coordinates of points, standard deviations, and ellipse of errors. The research is deal with some of the most common usage of statistical methods to detect these odds observations to confirm which best method is, by studying the advantages and disadvantages of each method to geodetic network. Three statistical methods will use in the analysis, these are:- 1. Standardized residuals method 2. F-t test 3. Robust estimation method The adjustments were accomplished by preparing a Matlab program with the three blunder detection methods and the results were evaluated and some scientific conclusions were reached. It was found that the robust estimation method represent the better blunder detection technique due to its ability in what is called (multi-blunder detection) , and the resulted higher accuracy indices.

Keywords

• Blunder detection, Geodetic Networks, Robust Estimation, Standardized Residual.