GIANT3D: experimentations on a new 3D data model for GIS

This paper describes phases of the development and results of an experimental structure of numerical cartography, at medium and large scale, to be used in GIS and to be proposed as a national standard. Development and results regarding software for writing and reading this model are reported too.Two of most important issues at the basis of modern cartography for GIS are open data format and three-dimensional content; another important required feature is a full topological structure with a shareable geometrical and semantic content.But the most recent requirement of modern cartography is interoperability: interoperability generally represents the borderline between the older and the newer way of thinking about GIS, and it includes data format, metadata, semantic, application, and service interoperability.So in order to define a new model of numerical cartography, compliant with technical needs mentioned above, 3D capable and interoperable, it's necessary to apply new rules and test the GML format that should grant interoperability.According to this goal, after the analysis of existing cartographic model, like OS MasterMap GML, CityGML, NEN3610, basing the work upon international standards (like ISO and OGC rules) a three-dimensional numerical cartography model has been implemented. This model is called GIANT3D, that means Geographical Interoperable Advanced Numerical Topological 3 Dimensional cartographic model. Software modules for editing and browsing this model has been realized.