Technical Trends in Geo Information

Transcription

1 Technical Trends in Geo Information Joachim WIESEL 1 Introduction Geo Information Systems as a small part of the IT-Industry is a fast changing technology, driven by market demands and technical advances. GIS is moving from a tool for specialists to a generally available service for citizens. Which technology trends will be important for GIS in the next couple of years? 2 Hard- and Software Trends 2.1 Hardware Trends As the GIS market is only small fraction of the general IT market, GIS has to use generally available computer and network devices. Personal computers based on the Windows/Intel architecture are powerful enough even for the most demanding tasks of today s GIS applications. Fast networks (Fast Ethernet, Gigabit Ethernet) are readily available and allow for instantaneous access to remote resources. Current Client/Server architectures are mainly based on so called Fat clients (e.g recent PCs) and servers delivering just data. Most processing is performed at the client side of the network. The disadvantage of this approach is: Cost of ownership is high, mostly because of software deployment and maintenance at the client side. Hardware for the clients is fairly expensive. Recent developments of end user devices are heading towards the Thin Client approach: Devices without hard disk, having just a network port, colour display, keyboard and pointing device. Software is downloaded on demand (e.g. by a built in Web Browser or Java Webstart). The main advantage of this approach is: Very low cost of ownership, software updates are downloaded automatically as needed. Mobile devices are getting better for GIS applications, as they are available now with colour displays and higher graphical resolution. Yet processing and memory resources are low and wireless networks (e.g. GSM UMTS in the future) are slow today and will be slow in the future compared to wire based nets. As more Thin Clients and mobile devices will be used in the future, servers have to be more powerful and reliable this trend could be called The return of the Mainframe. 2.2 Software Trends Software development today generally is object oriented and component based. Modern programming languages allow for OS- and even hardware independent software production (Sun ONE/Java, Microsoft.NET). Multi-tier architectures, like the one shown in Fig. 1 are used widely in all commercial IT projects.

2 2 J. Wiesel Fig. 1: Internet GIS architectures, fat server (left) vs. fat client (right) approach. (HOFMANN et al., 2000) 3 Internet The Internet and it s related networking protocols allow for easy communication between heterogeneous computers systems. HTTP (Hypertext Transfer Protocol) defines a stateless connection system, HTML (Hypertext Markup Language) and XML (extended Markup Language) describe documents and data sets, so dissimilar computers and operating systems can exchange structured data. In the GIS world, these technologies are used to enable clients (mostly consuming data and services) and servers (mostly providing data and services) to talk to each other. Geographical data sets or the result sets of spatial services, like buffering or selection by attribute, are being encoded using XML. Web browsers are the main user frontends to the net, often extended by plugins, scripting languages (e.g. ECMA-Script) or Java applets. Extensions are often required, as the HTTP does not support the high level of interactivity GIS applications often need (Fig. 1). All major companies are offering software packages for deploying Internet-GIS applications., which are often used by non-specialists performing simple tasks (e.g. ask for the owner of a parcel or add some attribute data to a spatial feature. 3D applications are beginning to enter the Internet field too: Languages like VRML (now X3D) and Java3D are used (in very different contexts) to implement applications like WAABIS (HILBRING et al., 2001) as shown in Fig. 3. Most desktop systems of today will be replaced by easier to maintain (but less powerful) internet based client/server applications.

3 Landscape Architecture in Reality-Virtuality, an Introduction 3 Fig. 2: GISterm multitier architecture showing the integration of different data providers and services (HOFMANN et al., 2000)

4 4 J. Wiesel Fig. 3: GeoPro3D for hydrological applications, showing planned buildings on top of a hydrogeological structure (HILBRING, WIESEL 2001) 4 Data Base Technology Without question the current object-relational approach of today s data base systems is an accepted technology, which is well understood by users and developers. The major data base software companies are offering spatial extensions to their base packages: Oracle Spatial, Informix Spatial Data Blade, IBM DB2 Spatial Extender, CA Ingres MM Extension, MS SQL Server. Some of them even have been certified by OGC to be conformant to the OGIS Simple Features Specification. All major suppliers of GIS software are supporting spatial databases as a back end to their desktop or client software packages: ESRI, Mapinfo, Intergraph, Smallworld, Sicad, Autocad to mention some either are supporting Oracle Spatial directly or via a layer of middleware software (e.g. SDE). The Open Source Community ( is on the way to develop a free implementation of OGC s Simple Features Specification based on PostgreSQL under the project name PostGIS.

5 Landscape Architecture in Reality-Virtuality, an Introduction 5 Most Internet based client/server systems are and will be based on a backend data base system, answering spatial queries. 5 Mobile Applications Mobile applications of GIS could extend the awareness of Geo technology. Location Based Services (LBS), consisting of mobile phones or smart phones will be the user interface to services with geographical content, e.g.: Where is the next gas station? Direct me to a nearby pharmacy... The backbone of these services are spatial database servers full of up to date spatial and attribute data (e.g.: opening times of gas stations). The location of a mobile phone can be determined by technical means of the phone operators to some 20 meters in urban areas and some kilometres in rural areas, depending on the size of the phone cells (BUHMANN & WIESEL, 2001). 6 Conclusions & Outlook IT technology is the driving force behind the trends in geo information. Today s standard GIS workstation will be just a tool for a small number of GIS specialists. Most applications in government and utility companies will be based on a multi tier client/server approach using strictly Internet protocols. Mobile applications are asking for accurate and up to date geo data. The management infrastructure for handling this task is not yet available (at least in Europe), while hard- and software for implementing the IT components is readily provided by the GIS industry today. 7 References Buhmann, E. & J. Wiesel (2001): GIS-Report Software Daten Firmen. Bernhard- Harzer-Verlag Karlsruhe, 2001, 302 S. Hilbring, D., C. Hofmann, Z. Veszelka, J. Wiesel, M. Müller (2001): GISterm Weiterentwicklung des flexiblen Frameworks zur Analyse und Visualisierung von raumbezogenen Daten. in R. Mayer-Föll, A. Keitel, A. Jaeschke (Eds.): Projekt AJA - Anwendung JAVA-basierter Lösungen in den Bereichen Umwelt, Verkehr und Verwaltung. Phase I 2000, Forschungszentrum Karlsruhe, Wissenschaftliche Berichte, FZKA 6565, S Hofmann, C., M. Weindorf & J. Wiesel (2000): Integration of GIS as a component in federated information system. Archives of the International Society for Photogrammetry and Remote Sensing (ISPRS), Vol. XXXIII, Part B4, Proc. ISPRS Congress, Amsterdam, pp Veszelka, Z. & J. Wiesel (2000): Performance Issues in Design and Implementation of GISter.; Archives of the International Society for Photogrammetry and Remote Sensing (ISPRS), Vol. XXXIII, Part B4, Proc. ISPRS Congress, Amsterdam, pp