National Spatial Data Infrastructure:
Concepts and Components
Douglas Nebert
U.S. Federal Geographic
Data Committee Secretariat
September 2004
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
Who needs access to coordinated
geographic information?
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
3
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)
4
Why build an 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
5
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 geoinformation through standards
7
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
Government Role in Infrastructure
National Interstate Highway system built for
defense logistics, now baseline for commerce
DARPA/ARPA advanced Internet
infrastructure design, establishing the
backbone
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!
Here’s one overview of the
pieces of the NSDI
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
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)
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’

Metadata
Geospatial Data
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 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
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 the core function of
the NSDI Clearinghouse for geospatial
information and the GOS geodata.gov portal
NSDI Clearinghouse Network and
geodata.gov portal
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 fulltext in the metadata and categorical browsing
Links through to full data access and online
web mapping services, where available
 A second
class 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 online data streaming services. These
services deliver ‘raw’ data, not maps.
Data Access Concepts
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
A third class of services provides
additional processing on geospatial
information
Discovery
Access Processing
Services
Metadata
Framework GEOdata
Processing Services
 These include capabilities that extend
and enhance the delivery of data
through processes applied to raw data:





Web Mapping Services
Symbolization
Coordinate Transformation
Analysis or topologic overlay services
Routing services
Standardization makes SDI work
 Standards touch every SDI activity

Discovery
Access
Processing
Services
Metadata
Framework GEOdata
Standards
Standards include specifications, formal
standards, and documented practices
FGDC Standards...
Created by 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!
Roles of standards bodies
Software interfaces
(Implementation
Specifications)
OpenGIS
Consortium
Other
NSDIs
Endorsed
practices and
specifications
NSDI
ISO TC 211
Foundations for
implementation.
(Abstract standards)
National
Standards
Content standards,
Authority for data
Partnerships extend our capabilities
Partnerships
Discovery
Access
Processing
Services
Metadata
Framework GEOdata
Standards
Partnerships are the glue...
FGDC has recognized 40+ geographic data
councils across the country to establish 2-way
coordination mechanisms
FGDC has funded numerous agencies with
“seed” funding to further existing efforts
along common lines
Partnerships extend local capabilities in
technology, skills, logistics, and data
The National Map is a partnership designed to
serve Framework data themes from
distributed participating organizations for
multiple purposes
Regional consortia
Locally formed, interdependent
Inclusive, voluntary, open
State, local, federal, tribal, academic,
private sector
Expanded from existing collaborations
29
Best practices
Treat data as strategic, capital assets
and public goods
Collaborate and Coordinate
Align roles, responsibilities and
resources for data stewardship
Organize Effective and Efficient
Production and Stewardship of Data
Pool and Leverage Investments
30
Effective regional consortia:
Address Institutional Barriers
Identify most effective ways to collect, maintain
and distribute Data
Determine business needs, inventory data
assets, identify gaps, estimate investment cost
Designate data stewards
Develop Enterprise Plans for Data production
and publication by the most appropriate partner
at accuracy and scale needed by local
jurisdictions
31
Effective regional consortia:
Aid State/local participation in Geospatial
One-Stop
Work with OGC on cutting edge of technology
(Semantic Translators and exchange
schemas, Web Services)
Help OMB and agencies in budget process
Enable role, responsibility, resource alignment
Provide, steward, and publish America’s Data
Assets
32
Treated together this comprises the NSDI
Partnerships
Discovery
Access
Processing
Clearinghouse
(catalog)
Services
Metadata
Metadata
Framework GEOdata
GEOdata
Framework
Standards
Douglas Nebert
Federal Geographic Data Committee Secretariat
ddnebert@fgdc.gov
http://www.fgdc.gov
(703) 648-4151
34
CAP Categories and the NSDI
Metadata Implementation
Partnerships
Discovery
1
Access
Processing
Services
Metadata
Framework GEOdata
Standards
Metadata Outreach and Training
Partnerships
Discovery
Access
Processing
Services
Metadata
2
Framework GEOdata
Standards
Institution Building and Coordination
Partnerships
Discovery
3
Access
Processing
Services
Metadata
Framework GEOdata
Standards
Web Mapping
Partnerships
Discovery
Access
Processing
Services
4
Metadata
Framework GEOdata
Standards
Web Feature Service and Framework
Partnerships
Discovery
Access
Processing
5 Services
Metadata
Framework GEOdata
Standards
Participation in The National Map
Partnerships
Discovery
6
Access
Processing
Services
6
Metadata
Framework GEOdata
Standards
6