Planimetric transformation for the overlap of the ancient Italian cadastral cartography on the current cartographic supports and evaluation of its metric accuracy

In Italy, at present, the cadastral cartography and every related service to citizen are managed by the Revenue Agency. It is important to remember the era of cadastral mapping formation, which has undergone many changes over time, dictated by the continuous evolution in the survey discipline.It is important to remember that the original maps were produced in the early 1900 with the Cassini-Soldner Projection on the Bessel's Ellipsoid. In the time, the ancient analogical methodologies for surveying and cartographic production have been gradually replaced with new analytical procedures and digital technologies that give higher accuracy, while new detection techniques and the GPS, in particular, introduced to the definition of a new International Geodetic Datum WGS84.During the eighties a process of digitalization of the cadastral cartography began, also introducing the first computerized procedures for the preparation of the deeds to update the land register. For these causes, the cadastral maps do not have a high metric accuracy and above all they cannot be superimposed on the more recent maps and orthophotos referred to the WGS84 International Datum. Therefore it is necessary and of scientific interest to explore the accuracy of the cadastral maps and its variations due to the digitalization process and the numerous updates made over time.