The Combined Method of Datum Transformation between Different Coordinate Systems

The similarity transformation method between different coordinate systems is not enough to describe the discrepancy of them. So the coordinate transformation from low precise coordinate frame to the high can not make sure a high precise reference frame after this transformation. In this paper, a combined method of similarity transformation and regressive approximating is presented. The local error accumulation and distortion are considered using the combined method and the precise of coordinate system is improved after the transformation using the recommended method.