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GIANT3D: EXPERIMENTATIONS ON A NEW 3D DATA MODEL FOR GIS
A. Scianna 3 ’ *, A. Ammoscato b , R. Corsale 0
a C.N.R. DAST - Dipartimento di Rappresentazione - Università di Palermo, viale delle Scienze c/o Facoltà di
Ingegneria, 90128 Palermo, Italy - scianna@dirap.unipa.it
b Dipartimento di Rappresentazione - Università di Palermo, viale delle Scienze c/o Facoltà di Ingegneria, 90128
Palermo, Italy - (alessio, rita)@dirap.unipa.it
WgS IV/1
KEY WORDS: Cartography, Databases, GIS, Interoperability, Data Structures, Building, Infrastructure
ABSTRACT:
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 modem 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 modem 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.
1.INTRODUCTION
This work starts from a national research project on numerical
cartography for GIS (PRIN 2004 “Strutture evolute della
cartografia numerica per I GIS e l'ambiente WEB”).
Needs for structuring national cartography come from
consideration that international model cannot be used as they
are because it's always necessary a conformation process to
make them compliant to national rules.
Particularly in Italy GIS data production (including cartography)
must be compliant to INSPIRE (Infrastructure for spatial
information in Europe) E.U. Directive.
2.CARTOGRAPHY FOR GIS
Today numerical cartography must satisfy a large number of
purposes and it has to be provided with specific characteristics
to be suitable for certain uses.
Development of CAD technologies for 3D modeling grew up
more quickly than tools for 3D GIS. Photorealistic solid models
interact with digital terrain models making a representation so-
called “City-model”. This is useful for browsing and
visualization of urban space, but it is not suitable for spatial
analysis. So a model of cartography should not be oriented only
to the visualization, but to the management of urban
transformations and the management of ownership too.
structured cannot be used or processed in advanced application,
like calculation a route on a graph could be impossible or very
difficult without topological rules.
Information's exchange and its revision are carried out by
advanced information systems; behind the need of a
georeferenced third-dimension information, GIS users very
often require tools to handle three-dimensional data.
Briefly, main topics related with handling cartography are:
- a standardized definition of contents of three-dimensional
cartography, dealing with nominal scale;
- multi-precision database handling and cartography's
generalization;
- a definition of a technical vocabulary or a system to share
and unequivocally identify objects, attributes and
relationships;
- a definition of a three-dimensional data model to
standardize geometrical, topological and thematic aspects;
- the use of the time as an important parameter to evaluate
territorial changes and development;
- data exchange and visualization using internet;
Another very important side of the modem numerical
cartography is interoperability; it 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.
In addition to the above, complying with topological rules can't
be considered as optional, because data that aren't topologically