Precise geodetic positioning based on the concept of variable datum transformation parameters

Abstract

Abstract Transformation between the World Geodetic System 1984 (WGS-84) and regional geodetic datums is the main objective of this investigation. In traditional methods, fixed values for the transformation parameters are used. They degrade the high accuracy that GPS provides to users and lead to large positional errors. Accordingly, the concept of using variable transformation parameters instead of fixed ones is proposed by this study. Since the three shift parameters are function of the position of points to be transformed, they were used in this research to test the quality of variable and fixed values of transformation parameters. This was accomplished using different polynomial surface fitting. The degree of the polynomials depends on the number and configuration of the available data points. Based on a practical application in Saudi Arabia, the method proposed by this study provides decimetre level of accuracy as compared with the few metres obtained by the traditional methods.