The application of the model of coordinate S-transformationfor stability analysis of datum points in high-precisionGPS deformation monitoring networks

Based on the model of coordinate S-transformation, a novel method of stability analysis of datum points in high-precision GPS deformation monitoring networks is proposed. The model of coordinate S-transformation is used to calculate seven transformation parameters in adjacent two measurement stages, in order to confirm the stability of stations by coordinate differences. To judge the stability of stations, in comparison to the traditional method by a fixed the same datum point, the “threshold approach” and “statistical test approach” have been developed and applied to evaluate the stability of datum points of a first-order GPS deformation monitoring network of a hydropower station located in the West Region of China.