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
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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
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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)
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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
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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
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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
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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 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
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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
Framework Data Standards
Eleven abstract data content standards
are being promulgated through the
ANSI process to become American
National Standards in 2005
Each thematic content standard has an
informative annex describing its
implementation as XML/GML Application
Schemas using OGC Web Feature
Services
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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
Geospatial Data Clearinghouse
The Geospatial Data Clearinghouse
Network includes nearly 300 distributed
collections of metadata searched via the
Z39.50 protocol, “GEO” Profile
geodata.gov harvests XML forms of
domestic metadata from Z39.50 and
browseable Web directories into a
searchable cache
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 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
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
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 (OGC WMS)
Symbolization (OGC SLD)
Coordinate Transformation (OGC WCTS)
Analysis or topologic overlay services
Routing services
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/
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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 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
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
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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
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Treated together this comprises the NSDI
Partnerships
Discovery
Access
Processing
Clearinghouse
(catalog)
Services
Metadata
Metadata
Framework GEOdata
GEOdata
Framework
Standards
Initiatives and Future Directions
Geospatial One-Stop and the
geodata.gov portal
An Enterprise Architecture for the NSDI
NSDI/FGDC Future Directions Initiative
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Geospatial One-Stop
One of 24 official E-Government
initiatives started in late 2002
Focused on the use and re-use of data
and services between government
(G2G) and the citizen (G2C)
Involves all sectors (federal, state, local
government, academia, commercial)
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How does OneStop support NSDI?
GOS has a timeline for implementation of
NSDI components by all partners
Deploys a “one-stop” portal (geodata.gov) for
quick access to community data, services, and
related resources
Standards are being developed with multisectoral 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
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Some operational features
geodata.gov will speed and simplify search
and browse of metadata as a replacement for
the domestic NSDI Gateways
Metadata are harvested from remote
collections into a single metadata ‘cache’ to
speed search and ranking
Browsing for geospatial data is made possible
through common ISO 19115 Topic Categories
Current portal is an operational prototype
based on research and development efforts,
March-September 2004
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Portal at geodata.gov
Map services can be registered and visualized
in viewer where links provided in metadata
(Online_Linkage)
Other resource types: Data, static maps, and
applications can be registered through
metadata
Channels (thematic communities) post and
arbitrate selected browseable content
Operational portal is to be awarded by
competitive procurement in Q1 2005
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Enterprise Architecture:
NSDI as the Enterprise
Develop an Enterprise Architecture for the NSDI
to encourage the identification of geospatial data
service producers and consumers, and optimize
resourcing for relevant programs within and
across agency lines
Deliverables to include:
Common terminology and scope to effort Business,
Data and Technology Reference models
 Validation of Reference Models via active prototyping
and demonstration
 A consensus process to evolve reference models via
broad NSDI Stakeholder / Community involvement

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NSDI Future Directions Initiative
Purpose: Draft a National Geospatial
Strategy for the further development of
the National Spatial Data Infrastructure
(NSDI)
Product: A Plan of Action for the FGDC
and the geospatial community
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Drivers
Revised OMB Circular A-16 (2002)
E-Government Act 2002 (Section 216)
President’s Management Agenda
Proposed Legislation
GAO Reports
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Future Direction Actions
Making Framework Real




Framework Standards
Development
Publishing Metadata
Implementing
Standards/Web Protocols
Urban Areas
Communicating The
Message



Partnerships with
Purpose




Restructure FGDC
Tribal Engagement
State Councils
Engaging Non-Geospatial
Organizations
Business Case
Strategic
Communications Plan
Training and Education
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Douglas Nebert
Federal Geographic Data Committee Secretariat
ddnebert@fgdc.gov
http://www.fgdc.gov
(703) 648-4151
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