Introduction to Spatial Data Infrastructure
- 2. What is an SDI? • “The SDI provides a basis for spatial data discovery, evaluation, and application for users and providers within all levels of government, the commercial sector, the non- profit sector, academia and by citizens in general.” The SDI Cookbook, http://www.gsdi.org, • A spatial data infrastructure (SDI) 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 (Wikipedia) • SDIs are defined as the technology, policies, standards, human resources, and related activities necessary to acquire, process, distribute, use, maintain, and preserve spatial data (Masser, 2005) • National Spatial Data Infrastructure (NSDI) means the technology, policies, standards, and human resources necessary to acquire, process, store, distribute, and improve utilization of geospatial data (Executive Order 12906, 1994) SDI
- 3. What is an SDI? SDI Like a road infrastructure makes it possible to connect different sites, a spatial data infrastructure makes it possible to connect data located at different sources Data easily discoverable and accessible to users Facilitating development of new applications and services
- 4. What is an SDI? SDI
- 6. SDI Hierarchy SDI SDIs are seen in many countries across the world as way to: • Increase efficiency of public administration by sharing information and processes • Contribute to open Public Sector Information increasing transparency in decision making, and new services, innovation, and jobs
- 7. Who needs access to coordinated geographic information? SDI • Land Records Adjudication • Disaster Response • Transportation Management • Water, gas & electric planning • Public Protection • Defense • Natural Resource Management • Telecommunications Infrastructure • Economic Development • Civic Entrepreneurs • Regional Stewards
- 8. Components of a Spatial Data Infrastructure (SDI) SDI • Policies & Institutional Arrangements (governance, data privacy & security, data sharing, cost recovery) • People (training, professional development, cooperation, outreach) • Data (digital base map, thematic, statistical, place names) • Technology (hardware, software, networks, databases, technical implementation plans)
- 9. Why build an SDI? SDI • Build data once and use it many times for many applications • Integrate distributed providers of data: Cooperative governance • “Place-based management” • Share costs of data creation and maintenance • Support sustainable economic, social, and environmental development
- 10. The outcomes of an NSDI • The participant members (contributors and users) are known and can interact • Core and specialized map and data services are easily discoverable and accessible • Decision-makers and analysts have ready access to the right geo- information for input to analytical and visual models – indicators, models, trends, patterns SDI
- 11. Benefits of an NSDI • Development of a private sector involved with data sales and added value • A chance for communities of all sizes and capabilities to participate in the knowledge economy • A more informed voter/citizen • Increased access to distributed geo-information through standards SDI
- 12. Creating the motivation • Development of an SDI should be a voluntary and have long-term vision • Government roles may require both incentives and directives • Commercial and non-commercial participants should find SDI appealing as a market • The correct solution for NSDI must be defined by the community SDI
- 13. Government Role in Infrastructure • Promotes standards to enable compatible solutions • We cannot imagine the fullest extent of how the NSDI will be populated or what applications will live upon it! SDI
- 14. overview of the pieces of the NSDI SDI The first task is to inventory who has what data of what type and quality A standardized form of metadata was published in June 1994 by the FGDC. An international standard now exists and will be adopted by the US beginning in 2005 Metadata
- 15. Metadata... • Provides documentation of existing internal geospatial data resources within an organisation (inventory) • Permits structured search and comparison of held spatial data by others (catalog) • Provides end-users with adequate information to take the data and use it in an appropriate context (documentation) SDI
- 16. Metadata Formats • The FGDC Content Standard for Digital Geospatial Metadata (CSDGM, 1998) is expressed in XML for exchange and text and HTML for presentation • Participants in the Geospatial Data Clearinghouse offer other metadata formats, including Dublin Core, ANZLIC, and expressions of ISO 19115 • Any metadata format can be presented by requesting the HTML format SDI
- 17. Metadata... Metadata describes existing data holdings for order, retrieval, or local use Metadata should be used to describe all types of data, emphasis on ‘truth in labeling’ SDI Metadata Geospatial Data
- 18. Geodata & Framework SDI Special-use thematic layers are built and described as available geospatial data Common data layers are being defined in the Framework activity Metadata Framework GEOdata
- 19. Framework supports... • Community development of sets of spatial features, feature representation, and attribution to a lowest common denominator • Participant collecting, converting, or associating information to common Framework data standards with an encoding format to facilitate exchange • Multiple representations of real-world features at different scales and times by feature identifier and generalization SDI
- 20. Framework Data Standards Each thematic content standard has an informative annex describing its implementation as XML/GML Application Schemas using OGC Web Feature Services SDI
- 21. Services The NSDI includes the services to help discover and interact with data SDI Services Metadata Framework GEOdata
- 22. Services… An important common service in SDI is that of discovering resources through metadata SDI Services Metadata Framework GEOdata This Discovery Service is the core function of the NSDI Clearinghouse for geospatial information and the GOS national geoportal
- 23. NSDI Clearinghouse Network and geodata.gov portal (Discovery) • Supports uniform, distributed search through a single user interface to all domestic metadata collections to find data and maps • A free advertising mechanism to provide world access to your holdings under the principle of “truth-in-labeling” • Search for spatial data through fields and full-text in the metadata and categorical browsing • Links through to full data access and online web mapping services, where available SDI
- 24. Access service A second class of services provides standardized access to geospatial information SDI Services Metadata Framework GEOdata This may be made via static files on ftp or via online data streaming services. These services deliver ‘raw’ data, not maps. Access Processing Discovery
- 25. Data Access concepts SDI • Standardisation of data access implies several things: • Definition of model used for the data to be exchanged • Adoption of an exchange or encoding format • Agreement on data access protocol(s) • Organisations should strive to identify the mode(s) of operation to simplify data exchange
- 26. Data Access Examples • Administrative boundary data conforming to the GlobalMap data model, packaged as Vector Product Format (VPF), made accessible over ftp • Panchromatic 10m, single-band, rectified imagery to a specific coordinate reference system, packaged as GEOTIFF with LZW compression, made accessible on CD-ROM SDI
- 27. Processing service SDI Services Metadata Framework GEOdata A third class of services provides additional processing on geospatial information Access Processing Discovery
- 28. Processing Services These include capabilities that extend and enhance the delivery of data through processes applied to raw data: Web Mapping Services (OGC WMS) Symbolization (OGC SLD) Coordinate Transformation (OGC WCTS) Analysis or topologic overlay services Routing services SDI
- 29. Geospatial Interoperability Reference Model (GIRM) • Voluntary technical participation in the NSDI is defined through the GIRM • The GIRM includes data standards, formats, protocols, and interface specifications to maximize interoperability • http://gai.fgdc.gov/girm/ SDI
- 30. Standards SDI Standardization makes SDI work Standards touch every SDI activity Standards include specifications, formal standards, and documented practices
- 31. FGDC Standards... • Created by FGDC working groups and thematic subcommittees as national standards, representing community consensus view of data theme or common approach • Submitted for 90-day public review • Reviewed across disciplines for uniformity • Published as US Federal Standards • Standards by ISO, OGC, W3C and other standardization bodies are used FIRST, if they exist! • http://www.fgdc.gov/standards/standards.html SDI
- 32. Roles of standards bodies
- 33. Partnerships extend our capabilities SDI
- 34. How does OneStop Geoportal support NSDI? • GOS has a timeline for implementation of NSDI components by all partners • Deploys a “one-stop” portal (National eoportal) for quick access to community data, services, and related resources • Standards are being developed with multi-sectoral stakeholders as national (ANSI) standards, not FGDC ones • Goals include measures of costs and savings through cost-sharing in data acquisition, processing, and service of geospatial data SDI