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Spatial Data Infrastructure Concepts and Components Douglas Nebert U.S. Federal Geographic Data Committee Secretariat August 2009
Spatial Data InfrastructureConcepts and Components
Douglas NebertU.S. Federal Geographic
Data Committee Secretariat
August 2009
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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
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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)
Here’s an overview of the elements and status of SDI…
Metadata
GEOdata
Clearinghouse (catalog)
Framework
Standards
PartnershipsPartnerships
MetadataMetadataMetadataMetadata
StandardsStandards
PartnershipsPartnerships
DiscoveryDiscovery AccessAccess
Services
ProcessingProcessing
FrameworkFramework GEOdataGEOdata
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
MetadataMetadataMetadataMetadata
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
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’
MetadataMetadataMetadataMetadata
Geospatial DataGeospatial DataGeospatial DataGeospatial Data
ServicesServicesServicesServices
Special-use thematic layers are built and described as available geospatial dataCommon data layers are being defined in the Framework activity
MetadataMetadataMetadataMetadata
FrameworkFramework GEOdataGEOdata
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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)
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Scope: Framework LayersElevationOrthoimageryHydrographic DataGovernmental Unit BoundariesCadastralGeodetic ControlTransportation Roads Air Rail Marine Transit
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Interoperability with common Framework data encoding
System 1
System 3
System 2APIexport
import
API
export
import
WFS
CoreFrameworkEncoding
ServicesServicesServicesServices
The NSDI includes the services to help discover and interact with data
MetadataMetadataMetadataMetadata
FrameworkFramework GEOdataGEOdata
This Discovery Service is provided by a national catalog of geospatial information which can be accessed by a national portal
Services
An important common service in SDI is that of discovering resources through metadata
DiscoveryDiscovery AccessAccess ProcessingProcessing
MetadataMetadataMetadataMetadata
FrameworkFramework GEOdataGEOdata
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National Geo-Portal capabilities
Help locate data and servicesSupport download of data, link to related websites, and applications for others to accessSupport self-organizing communities post and manage selected contentShare data collection plans and requirements to support partnerships and collaboration
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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
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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
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metadatacatalog
Portal
map viewer
metadata
metadata
metadatametadatadata
data
data
data
formentry
XMLupload
search
map services
ServicesDiscoveryDiscovery AccessAccess ProcessingProcessing
This may be made via static files on ftp or via web services. These services deliver ‘raw’ geospatial data, not maps.
A second category of services provides standardised access to geospatial information
MetadataMetadataMetadataMetadata
FrameworkFramework GEOdataGEOdata
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Interoperable data accessWeb
Serverform
postgreSQL ArcSDE
Minnesotamapserver ArcIMS
Access
Deegree
OGC WMS Request
OGC WMSServices
NativeServices
AutoCAD
GeoMedia
Oracle
MapExtreme
Distributed provider organizations
ServicesDiscoveryDiscovery AccessAccess ProcessingProcessing
A third class of services provides additional processing on geospatial information
MetadataMetadataMetadataMetadata
FrameworkFramework GEOdataGEOdata
Standardization makes SDI work Standards touch every SDI activity
DiscoveryDiscovery
StandardsStandards
AccessAccessServices
ProcessingProcessing
Standards include specifications, formal standards, and documented practices
MetadataMetadataMetadataMetadata
FrameworkFramework GEOdataGEOdata
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SDI Suite 1.0 CandidateOGC 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
Candidate “SDI 1.0” Standards
Partnerships extend our capabilities
StandardsStandards
PartnershipsPartnerships
DiscoveryDiscovery AccessAccess
Services
ProcessingProcessing
MetadataMetadataMetadataMetadata
FrameworkFramework GEOdataGEOdata
Partnerships are the glue...
Proper governance of the community is essential through a variety of roles and responsibilitiesNational government or NGOs should partner with other levels of government and sectors to promote 2-way coordinationThe government or a foundation may be able to fund agencies with “seed” funding to further existing efforts toward common goalsPartnerships extend local capabilities in technology, skills, logistics, and data
