Crack and sometimes break, under the burden,
Under the tension, slip, slide, perish,
Decay with imprecision, will not stay in place,
Will not stay still. Shrieking voices
Scolding, mocking, or merely chattering,
Always assail them."
– T. S. Eliot, American poet and playwright, Four Quartets, 1935
In the past decade the geospatial industry has seen the emergence of a host of similar terms to try and describe what the industry is all about and where it is going. Words like "SDI", "Geomatics", "Spatial Infrastructure", "Ubiquitous Geographic Computing", "Location Intelligence", "Location Based Services", "Geospatial Intelligence", and of course "GeoWeb". This proliferation of terminology reflects both a confusion in the industry, and an attempt to understand it. We know that the general rubric of "GIS" is both too generic , and too limiting, but we are not sure what to use in its place. Such confusion is of course typical of domains which are undergoing rapid change and which are being pulled in many directions by a wide array of market, social and technology forces.
This article attempts to clarify the situation by offering some definitions and equivalences to help reduce the terminology clutter.
To begin with let's redefine the term GIS to mean all and any information system or systems that deal with Geography or Geographic information. So everything we talk about is then GIS. Effectively GIS and Geomatics are then synomyms. Think GIS = Geomatics = automation of geographic information handling. These terms then cover all aspects from data acquisition (e.g. surveying, remote sensing) to cartography, map production, analysis, and all forms of applications that make use of geographic information. Of course such a generalization leaves open the real issues that confront us and how to talk about them, but we can at least dispense with GIS or Geomatics as the right words, other than for the very general umbrella. All of the others must pertain to concepts or ideas within the domain of GIS/Geomatics or overlap between this domain and other areas of Information Technology.
The dominant force for change in the Geomatics world (I'll use just the one word henceforth) is the increasingly everywhere connectivity of information systems. Don't think in terms of wireless or mobility – these are just technologies – think in terms of everywhere connectivity. The same effects could be obtained, and will be in many cases, using RFID's or other local place identification mechanisms.
One might ask why everywhere connectivity should have such a deep impact on geomatics? It might seem to be a supreme irony that the nearly universal transparency of location should have such a huge impact on the world of geomatics, but there is a reason for this. It is what I would call the information integration imperative and this was a major driver for the desk top GIS systems of the 1980's. Every action that we humans take in the world (or which is taken by the world) has consequences and impacts far beyond the action itself. As a consequence, any attempt to deal with the world, whether in terms of engineering design, or emergency response, requires that we integrate information from a host of sources and disciplines. This is made still more difficult by the fact that the world is divided into a vast array of complex and overlapping jurisdictions. Effective decision making of any kind demands that this information be integrated. Everywhere connectivity makes this integration possible, and more over makes it possible to provide the results of this integration to any point on the planet. "Location Services", "Location Intelligence" are thus technologies that deal with the provision of integrated information or the results of information integration to a user regardless of their location. The terms do not however deal with the act of integration itself.
A companion driving force to that of everywhere connectivity is that of everywhere position determination – one of the fundamental location services – determining where in the world something is located. Everywhere position determination complements everywhere connectivity (the latter is precondition for the former) by greatly enriching the sources of information, and by enabling the provision of information not just about a place, but more importantly about a thing such as a person or a vehicle, whether fixed or in motion. This in turn has enabled information consumers – consumers of location services – to themselves be participants in information creation and hence in information integration. Knowing where you are is of no help if you don't know what is around you.
The term "Ubiquitous Geographic Computing" can be seen as implying everywhere connectivity and everywhere position determination, but should not be seen as representing any particular geomatics technologies. One should think of ubiquity as a given aspect of all future information technologies and not a technology in itself.
So what then about SDI and GeoWeb? Both of these terms imply information integration. What's the difference? How much of this is really to do with geomatics? I would argue that GeoWeb is the more general term and refers both to the subject of local and global geographic data integration, and to the technologies for realizing that integration. "SDI" and "Spatial Infrastructures" are community implementations of technology for information sharing, and should be understood as implying real time integration of information and associated services. This means that the GeoWeb, as a noun, can be seen as the integration of many SDI's into a web of integrated information potentially spanning the globe, hence dealing with the integration imperative and providing community integration and global accessibility. Note that the notion of a community (also data community, information community) may be bound to a place (e.g. a municipality or region) or may be location independent (e.g. community of oceanographers world-wide).
Make sense? I am sure this discussion has only scratched the surface – but I hope it has in some way cleared the air.
"For last year's words belong to last year's language
And next year's words await another voice."
-T. S. Eliot, American poet and playwright, Four Quartets, 1944