Residual Filtering Methods for the Purpose of Computing the Coordinate Transformation Distortion Model

For the purpose of coordinate transformation between two different horizontal geodetic data, the inherited one, the Croatian State Coordinate System (HDKS) and the new (official) one, Croatian Terrestrial Reference System 1996 (HTRS96) utilizing seven parameters coordinate transformation (Bursa–Wolf model) and distortion model, three methods of residual filtering were introduced in this paper, using our own developed algorithms. Each algorithm is based on a different ratio: the ratio of resultant residual and surface function of point’s environment, the ratio of difference and mutual distance of neighboring resultants in the area, and the ratio of difference and mutual distance of neighboring resultants in tangential plane. Thus, the concept of the theoretical residuals has been introduced, as well as the idea of semi–iterative procedure that is conducted through the automatization of filtering in spatial or just in plane sense and operates on the principle of a combination of classic Bursa–Wolf transformation and TIN tessellation under the terms of Delaunay’s triangulation and Voronoi’s polygons