A method is presented in this paper for solving a practical problem: how to make georeferenced mosaic of a map series using ground control points and quadratic polynomial transformation for every individual map sheet, if we expect, that after georeferencing the edges of the transformed map sheets should fit together.To solve this problem we can use a constrained polynomial fit method. In this method we use least square adjustment to get the transformation parameters for every individual map sheets, and we define constrains, that the common edges of every two neighboring map sheet should transform similarly. Solving this equation we get the transformation parameters for every single map sheet. Using these parameters for transforming the map sheets, we get georeferenced maps, that automatically fit together in a GIS software.This method has been successfully applied for georeferencing 18 map sheets of the First Topographic Survey of the Habsburg Empire. The resulting georeferenced map has larger residual errors than the individually transformed map sheets, but in exchange for we get a seamless map mosaic, that is more accurate, than the graphically merged and transformed.
Hofstätter E 1989: Contributions to the history of the Austrian surveys (in German), Part I. Bundesamt für Eich- und Vermessungwesen, Wien