Types of GIS
N.B.: The following GIS types are not necessarily mutually exclusive and a GIS application can be always classified under more than one type.
While spatio-temporal geo-representations can handle two dimensions of space and one of time, four-dimensional GIS are designed for three dimensions of space and one of time.
Multimedia/hypermedia GIS allow the user to access a wide range of georeferenced multimedia data (e.g., simulations, sounds and videos) by selecting resources from a georeferenced image map base. A map serving as the primary index to multimedia data in a multimedia geo-representation is termed a hypermap. Multimedia and virtual geo-representations can be stored either in extended relational databases, object databases or in application-specific data stores. Raper (2000) mentions several examples including a multimedia atlas that has been developed for the tourist information system in China.
Imagine having a real-time (using telecommunication links) multimedia GIS that can audio-visually monitor different locations at the same time; one application of such system could be as a decision support tool to improve the analysis of traffic problems and the assessment of noise in urban planning and management.
Since video is a spatio-temporal projection of the world in imagery, it can be considered capable of fully multi-dimensional geo-representation. It can be used for mapping from moving platforms, for target positioning, for the measurement of geo-phenomena such as air pollution, and as a process monitoring system. Video imaging has also become a recognised and valuable new technique of remote sensing since the 1990s.
Widespread access to the Internet, the ubiquity of browsers and the explosion of commodified geographic information has made it possible to develop new forms of multimedia geo-representations on the Web. ESRI, for example, provides a good range of Internet mapping solutions based on their RouteMAP IMS and ArcIMS (Internet Mapping Server) architectures.
Many current geomatics solutions are Web-based overtaking the traditional Desktop environment and most future one are expected to follow the same direction.
Virtual Reality GIS
Virtual Reality GIS have been developed to allow the creation, manipulation and exploration of geo-referenced virtual environments, e.g., using VRML modelling (Virtual Reality Modelling Language). Virtual Reality GIS can be also Web-based. Applications include 3D simulation for planning (to experiment with different scenarios).
With the availability of real-time positioning systems and cost-effective mobile telecommunications, it has become possible to develop real-time GIS that monitor, transmit, record and analyse the movement of mobile agents such as vehicles, people or animals (telegeomonitoring). In transportation for example, many organisations need to monitor the position of their vehicles for scheduling or safety reasons. Each mobile agents transmits positioning information to the appropriate control centre(s), where it is entered into a database of time-stamped positions. Some applications can monitor the proximity of the mobile agents to specified locations or advise on alternative routes based on traffic reports. Imagine such applications in the context of an ambulance fleet of cars. Real-time GIS can also include location-based services, where a moving agent receives information depending on its location (GMS - Geographic Messaging Services), e.g., in tourism, giving and updating relevant details of attractions to tourists as they approach different areas.
Raper J. Multidimensional Geographic Information Science. London: Taylor and Francis. 2000 [ISBN 0-7484-0507-0]