Spatial Data Infrastructure Concepts and Components Douglas Nebert U.S. Federal Geographic Data Committee Secretariat August 2009
What is a Spatial Data Infrastructure (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 2
Components of a Spatial Data Infrastructure (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) 3
Here s an overview of the elements and status of SDI
Partnerships Discovery Clearinghouse (catalog) Metadata Framework Access Services Framework GEOdata GEOdata Standards Processing
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 US FGDC. An international standard (ISO 19115/19139) now exists and is being adopted by most countries Metadata
Metadata can apply to data, services, and other resource types Provides documentation of existing internal geospatial resources within an organisation (inventory) Permits structured search and comparison of held geospatial resources by others (catalog) Provides end-users with adequate information to take the resource and apply it in an appropriate context (documentation) ISO 19115/TS19139 provide an international standard for metadata and its encoding
Services Metadata Geospatial Data Metadata describes data and service resources for order, access, or local use Metadata is used to describe all types of data, emphasis on truth in labeling
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
Framework Data Standards Eleven abstract data content standards are being promulgated through the ANSI process as American National Standards Each theme (layer) is also described as XML/GML Application Schemas that can be served over the Web (OGC Web Feature Services) 11
Scope: Framework Layers Elevation Orthoimagery Hydrographic Data Governmental Unit Boundaries Cadastral Geodetic Control Transportation Roads Air Rail Marine Transit 12
Interoperability with common Framework data encoding System 1 import API export Core Framework Encoding export API import System 2 WFS System 3 13
The NSDI includes the services to help discover and interact with data Services Metadata Framework GEOdata
An important common service in SDI is that of discovering resources through metadata Discovery Access Processing Services Metadata Framework GEOdata This Discovery Service is provided by a national catalog of geospatial information which can be accessed by a national portal
National Geo-Portal capabilities Help locate data and services Support download of data, link to related websites, and applications for others to access Support self-organizing communities post and manage selected content Share data collection plans and requirements to support partnerships and collaboration 16
Functional Areas in the Portal Search enables users to find geospatial data Communities highlight authoritative data sources Featured Resources highlight maps, applications and websites of current interest 17
Metadata Publication Options Users may contribute metadata one of three ways: Enter metadata into a form on the catalog and they are stored and indexed there Upload metadata as XML to the catalog from a GIS or metadata program Register their existing metadata collection or service to be harvested into the national catalog 18
data metadata data metadata form entry metadata catalog XML upload search Portal map viewer map services data metadata data metadata 19
A second category of services provides standardised access to geospatial information Discovery Access Processing Services Metadata Framework GEOdata This may be made via static files on ftp or via web services. These services deliver raw geospatial data, not maps.
Interoperable data access Web Server form OGC WMS Request OGC WMS Services Native Services Minnesota mapserver Deegree ArcIMS GeoMedia MapExtreme postgresql Access ArcSDE AutoCAD Oracle Distributed provider organizations 21
A third class of services provides additional processing on geospatial information Discovery Access Processing Services Metadata Framework GEOdata
Standardization makes SDI work Standards touch every SDI activity Discovery Access Services Processing Metadata Framework GEOdata Standards Standards include specifications, formal standards, and documented practices
Candidate SDI 1.0 Standards SDI Suite 1.0 Candidate OGC Web Map Service 1.1.1 OGC Web Feature Service 1.0 OGC Filter Encoding 1.0 OGC Web Coverage Service 1.0 OGC Geography Markup Language 2.1.2 OGC Catalog Services 2.0 Z39.50 Protocol Binding FGDC Content Standard for Digital Geospatial Metadata (CSDGM, 1998) SDI Suite 1.0 Supplemental ISO Metadata Standard 19115 and ISO TS 19139 OGC Geography Markup Language 3.1.1 OGC Styled Layer Descriptor 1.0 OGC Web Map Context 1.1 OGC Catalog Services 2.0 HTTP Protocol Binding, CS-W 26
Partnerships extend our capabilities Partnerships Discovery Access Services Processing Metadata Framework GEOdata Standards
Partnerships are the glue... Proper governance of the community is essential through a variety of roles and responsibilities National government or NGOs should partner with other levels of government and sectors to promote 2-way coordination The government or a foundation may be able to fund agencies with seed funding to further existing efforts toward common goals Partnerships extend local capabilities in technology, skills, logistics, and data
Thank you! Doug Nebert US Federal Geographic Data Committee ddnebert@usgs.gov +1 703 648 4151 29