Horizontal datum transformation by distortion modelling in Korea

Abstract

This paper describes the development of a transformation grid for transforming horizontal spatial data from the local geodetic datum to a geocentric datum in Korea. We used least squares collocation as the method for modelling the distortion that remains after the application of a standard seven-parameter similarity transformation. In the experimental tests, the RMSEs in latitude and longitude coordinates are ±0.016m and ±0.007m, respectively, after the distortion modelling, whereas it was indicated that transformation accuracy is improved about 98% by distortion correction. This is a reasonable result, which should give users confidence in transforming data from the local geodetic datum to the geocentric and vice versa for medium scale maps.