Spatial Data Infrastructure
Spatial Data on the Internet
In more recent definitions of SDI it translates into "Spatial Data on the Internet". The main reason for this slight shift in perspective is that there is no reason to try and define a separate infrastructure for spatial data if a perfectly well organized infrastructre is already in place (the Internet and the Web).
The legacy definition of a Spatial Data Infrastructure (SDI) is an infrastructure to provide interactively connected access to spatial data and metadata using software tools. Modern SDIs are typically implemented as interoperable Web services which are designed as resources. In the resource oriented paradigm the interaction occurs by exchanging stateless representations of the resources.
In broader definitions an SDI as the sum of the technology, policies, standards, human resources, and related activities necessary to acquire, process, distribute, use, maintain, and preserve spatial data. Kuhn (2005) defines an SDI is a coordinated series of agreements on technology standards, institutional arrangements, and policies that enable the discovery and use of geospatial information by users and for purposes other than those it was created for.
Application of SDI Design
- Towards a Resource Oriented Future
- The blog The Hierarchy and the Graph describes the basics needed to understand how the SDI lives in the Internet and on the Web.
- The presentation SDI in Germany: Complying with INSPIRE given at FOSS4G 2010 gives an introduction to how SDIs are implemented in Europe.
- The PDF slide set Pollutant Release and Transfer Registry - Germany given at FOSS4G 2009 shows how an SDI can be used to provide dynamic information provided by the government to the citizen.