Interoperability on the Web: the Case of 3d Geo-data

Geographic information (also called geo-information, spatial information or geospatial information) plays an increasingly important role in our society. Location Based Services, applications for urban planning, disaster management systems rely on geo-data and in many cases up-to-date geo-information is crucial, e.g. in disaster response systems. In this paper we focus on a special kind of geo-information: 3D spatial data to be used in 3D GIS (Geographic Information System), CAD (Computer Aided Design), Virtual Reality or Augmented Reality applications. Because the production of up-to-date and accurate geo-information is very costly, exchanging and sharing data between organizations is often the only way to get all relevant information to decision makers and other end users. In principle Internet has created new possibilities for the shared use of geo-data. Data sets do not have to be copied anymore on CD’s or tape, but could be accessed online, via Web services. Progress towards shared use of geo-data via the Web is slow however. One of the bottlenecks is the heterogeneous nature of geographic data, both in a technical sense (data format) and in a semantic sense (data model and meaning). Interoperability (of data and software) is therefore a key issue that needs to be resolved. In this paper we will look at the interoperability initiatives of the OpenGIS Consortium (OGC). One of the main principles of OGC is, that in order to improve data and software interoperability, it is necessary to create standardized interfaces between the different components (possibly of different vendors) of geo-information systems. We will investigate possibilities to publish 3D geo-data on the Web using OpenGIS compliant Web services. We will report on a 3D Web Mapping prototype environment built at our research institute. One purpose of the prototype is to see whether the present OGC specifications are adequate for access to 3D geo-data (query, visualization, navigation and analysis). Apart from the OpenGIS Web service specifications also another emerging Web standard is used in the prototype: X3D (eXtensible 3D) of the Web3D Consortium.