Georeferencing the historical maps of Rome between the seventeenth and the eighteenth centuries

Abstract

lelo@uniroma3.it ABSTRACT Historical studies often need to consider both geographic and temporal aspects of the analysed phenomenon. At present, Geographical Information Systems (GIS) can provide historians with a series of extremely useful tools for analysing the territory and its temporal transformations. As already known, historical maps may lack of geographic reference systems or may be expressed in systems which are substantially different from the contemporary ones. The georeferencing of this kind of documents can be performed through the identification of points remained unchanged over time, univocally recognizable in the historical map as well as in actual cartography and/or in the terrain, to be used as tie points. This procedure bears limits of metric precision, but in most of the cases results to be the only one applicable. In this paper we analyse the procedure of georeferencing historical cartography by means of a GPS campaign of measurements, and further on, investigate the conditions of comparison with recent small scale digital cartography, in order to evaluate its eventual use for georeferencing the historical maps.