A
spatial data infrastructure (
SDI), also called
geospatial data infrastructure,
is a data infrastructure implementing a framework of
geographic data, metadata, users and tools that are interactively connected in order to use spatial data in an efficient and flexible way. Another definition is "the technology, policies, standards,
human resources, and related activities necessary to acquire, process, distribute, use, maintain, and preserve spatial data".
[The White House, Office of Management and Budget (2002) Circular No. A-16 Revised, August 19, 2002] Most commonly, institutions with large repositories of geographic data (especially government agencies) create SDIs to facilitate the sharing of their data with a broader audience.
A further definition is given in Kuhn (2005):[Kuhn, W. (2005) presentation "Introduction to Spatial Data Infrastructures". Presentation held on March 14, 2005.] "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."
General
Some of the main principles are that data and metadata should not be managed centrally, but by the data originator and/or owner, and that tools and services connect via
to the various sources.
[Steiniger, S., and Hunter, A.J.S. (2012) preprint "Free and open source GIS software for building a spatial data infrastructure". In E. Bocher and M. Neteler (eds): Geospatial Free and Open Source Software in the 21st Century: Proceedings of the first Open-Source Geospatial Research Symposium, 2009, LNG&C, Springer, Heidelberg, pp. 247-261.] A
GIS is often the platform for deploying an individual node within an SDI. To achieve these objectives, good coordination between all the actors is necessary and the definition of standards is very important.
The original example of an SDI is the United States National Spatial Data Infrastructure (NSDI), first mandated in the OMB Circular A-16 in 1996. In Europe since 2007, INSPIRE is a European Commission initiative to build a European SDI beyond national boundaries; the United Nations Spatial Data Infrastructure (UNSDI) plans to do the same for over 30 UN Funds, Programs, Specialized Agencies and member countries.
Software components
An SDI should enable the discovery and delivery of spatial data from a data repository, via a spatial service provider, to a user. As mentioned earlier it is often wished that the data provider is able to update spatial data stored in a repository. Hence, the basic software components of an SDI are:
-
Software client - to display, query, and analyse spatial data (this could be a web browser or a desktop GIS)
-
Catalogue service - for the discovery, browsing, and querying of metadata or spatial services, spatial datasets and other resources
-
Spatial data service - allowing the delivery of the data via the Internet
-
Processing services - such as datum and projection transformations, or the transformation of cadastral survey observations and Ownership requests into Cadastral documentation
-
(Spatial) data repository - to store data, e.g., a spatial database
-
GIS software (client or desktop) - to create and update spatial data
Besides these software components, a range of (international) technical standards are necessary that allow interaction between the different software components.[Global Spatial Data Infrastructure Organisation - The SDI Cookbook. link to cook book wiki] Among those are geospatial standards defined by the Open Geospatial Consortium (e.g., OGC WMS, WFS, GML, etc.) and ISO (e.g., ISO 19115) for the delivery of maps, vector and raster data, but also data format and internet transfer standards by W3C consortium.
National spatial data infrastructures
List by country or administrative zone. It is not complete, is a sample of National Spatial Data Infrastructure (NSDI) official websites.
See also
External links
- Journals
- Books
- Software
-
geOrchestra is a free, modular and interoperable Spatial Data Infrastructure software that includes other software like GeoNetwork, GeoServer, GeoWebCache,...,
-
GeoNetwork is a Free software (FOSS) cataloging application for spatially referenced resources,
-
GeoNode is a web-based application and platform for developing geospatial information systems (GIS) and for deploying spatial data infrastructures (SDI),
-
OpenSDI includes Open Source components like GeoServer and GeoNetwork,
-
easySDI is a complete web-based platform for deploying any geoportal.
-
Geoportal Server is an open source solution for building SDI models where a central SDI node is populated with content from distributed nodes, as well as SDI models where each node participates equally in a federated mode.
