Generalised Procrustes Algorithms for the Conformal Updating of a Cadastral Map

Referring to the current Italian cadastral map updating system, the paper describes an innovative analytical method to perform the general adjustment of the fiducial point network, and the optimal conformal insertion of new surveyed cadastral parcels into an already existing digital map. Working on the surveyors’ data files containing the distance values between couples of fiducial points, the proposed procedure reciprocally fits, in the least squares sense, the various and corresponding fiducial polygons, as unitary component parts of the general fiducial network, by way of similarity transformation adjustment models computed by Generalised Procrustes algorithms. The proposed method satisfies and advantageously preserves the geometrical shape of the original surveys. This property allows the conformal mosaicking of the new surveyed cadastral entities with those ones obtained by digitisation of the original map, respecting also possible geometrical constraints of the map entities. Finally, some numerical examples show the precision and the accuracy of the method proposed.