Standards and the US National
Spatial Data Infrastructure
Improving access to geospatial
information
Overview
FGDC and GIS Standards
Division of labor in standardization
2
FGDC Objectives
To promote access to and usage of
digital geospatial information of national
and local value
To improve discovery of and public
access to federal geospatial data
resources
To reduce duplication of effort among
public sector organizations developing
geospatial data
3
FGDC and Standards
FGDC provides a public forum for the
development of content-based
standards for general or information
community use
Examples:


Content standard for digital geospatial
metadata
Framework data standards
4
Endorsement of External
Standards
In 2010, the FGDC endorsed a set of
64 external geospatial standards as a
reference set for community use
Derived from a much longer list of DoD
IT Standards Registry (DISR)
Point of collaboration with the
Geospatial-Intelligence Standards
Working Group (GWG)
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6
ISO Standards (TC 211)
FGDC participates in ANSI/ISO
standardization under ISO TC-211
Some areas of participation:




Metadata content standard
Services
Encoding
Data Quality
7
FGDC and OGC
FGDC participates in the Open
Geospatial Consortium for the
development of common
implementation specifications to
improve access to spatial information
Users benefit from vendor support of
information access specifications and
integration of solutions into GIS
workflow
8
OGC Specifications
Designing implementation solutions for
discovery through Catalog Services
Approved: Simple Features SQL, KML, Web
Map Server Specification, Geography Markup
Language (GML), Catalog Services
Specification, Web Coverage Services, Web
Feature Services, Sensor Observation Service
Going beyond Simple Features to raster
(coverage) services and eventually distributed
GIS
9
GIS Standards Turf
ISO TC-211 is focused on the abstract
specifications, design framework and
international political consensus (what)
National standards support the
development of community content
standards (who, why)
OGC specializes in extending the
abstract model into implementation
specifications (how)
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SDIs and Standards Advocacy
Software interfaces
(Implementation
Specifications)
Regional
SDI Coordination
OpenGIS
Consortium, W3C
Other
NSDIs
Endorsed
practices and
specification
s
SDI
ISO TC 211
Foundations for
implementation.
(Abstract standards)
National
Standards
Content standards,
Authority for data
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UI
UI
managed
through
Metadata
managed
through
Metadata
DB/Index
are
loaded
to or
stored in
Spatial
Data
is exposed
to the Internet
through a
managed
through
UI
Symbols
now:
planned.:
enter/update
synchronize API
performs lookup
to grab operation
signatures
API
is exposed
to the Internet
through a
makes
maps
from
draws
layers
from
Web Mapping
Service
Other
Service
Interface
Function
Catalog
Client
may send
data to
GEOdata
Access
Service
feeds
server info
to
distributes to
and collates
from multiple
enhances
query
with
provides
application 1
access
through
API
UI
managed
through
Service
Registry/
Catalog
SDI Interaction
interacts with
Diagram
Application
revised 7-May-2003
ddnebert@fgdc.gov
Client
API
API
API
Gateway
API
2
Software/Service
Information
API
UI
are derived
for each
may reference
instances
Data/File
stored in
Management
System
current planned
Data Catalog
Service
UI
queries
may be
coupled
to or
integrated
with
are
derived
from
stores service info
Metadata
UI
Gazetteer
enhances
query
with
3
Thesaurus
1. builds query screens for
2. submits queries/requests to
3. returns search responses
interacts with
Web Client
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Standards are monolithic yet
interdependent
WFS
1.0
may return
deployed as
used for
transport
XML
validates
HTTP
GML
3.0
validates against
XML
Schema
transformable to
UML
harmonized with
ISO
Spatial
Schema
expressed in
13
Framework Themes
Themes providing the core, most
commonly used set of base data are
known as Framework Data:







Geodetic Control,
Orthoimagery,
Elevation and Bathymetry,
Transportation,
Hydrography,
Cadastral, and
Governmental Units.
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Additional Data
Geographic names (toponymy) layer
Land cover/vegetation/wetlands
Cultural and Demographic Statistics
Buildings and Facilities
Natural hazards
Soils and Geology
Utility distribution networks
15
Framework Standards
In 2008, the FGDC published eleven
Framework standards
Included an abstract model (in UML)
and had companion XML schema files
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Design Process
Community
6. Forward Draft for
Review and Approval
3. Review
1. Requirements
4. Comments
ApplicationNeutral
Content Model
2. Design
5. Refine
Modeling Advisory
Team (Team of Experts)
Encoding
(XML)
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Conceptual Model
A conceptual or logical design of the
information that preserves the native
groupings of the data
Is implementation- and software-independent
to provide a stable base for current and
future implementations
Describes graphically and with narrative the
design assumptions and conditions
Currently expressed using the Unified
Modeling Language (UML)
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What is UML?
Unified Modeling Language
UML is an industry standard language for
visualizing, specifying, constructing, and
documenting artifacts of a softwareintensive system
Platform-neutral environment for abstract
modeling of data and processes
Adopted as the Conceptual Schema
Language for ISO TC 211
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UML Diagrams
Use Case
Use Case
Diagrams
Sequence
Diagrams
Diagrams
Scenario
Scenario
Diagrams
Collaboration
Diagrams
Diagrams
Scenario
Scenario
Diagrams
Statechart
Diagrams
Diagrams
Use Case
Use Case
Diagrams
Use Case
Diagrams
Diagrams
State
State
Diagrams
Class
Diagrams
Diagrams
Models
State
State
Diagrams
Object
Diagrams
Diagrams
State
State
Diagrams
Component
Diagrams
Diagrams
Component
Component
Diagrams
Deployment
Diagrams
Activity
Diagrams
Diagrams
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Class Diagram
Captures the ‘vocabulary’ of a system
Built and refined throughout development
Purpose



Name and model concepts in the system
Specify collaborations
Specify logical database schemas
Developed by analysts, designers, and
implementers
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UML Class Diagram
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The UML
Useful for diagramming systems, objects, and
relationships
Many diagrammatic conventions
Many ways to diagram the same thing
Can serialize the UML as XML (XMI)
CASE tools or transforming programs can create
implementation bindings
FGDC is hosting a UML-to-GML transform
program for convert UML into XML Schema
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UML per Rational Rose
Implementations
Conceptual
Models
Oracle
Table
Schema
User
Interface
Integrated
Development
Environment
UML
procedures
and structures
Java
Program
Code
XML
Schema
Document
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Start Modeling
Review existing models from FGDC and
The National Map efforts and
adapt/adopt them if possible
Identify theme experts who are either
producers or users of digital geographic
data
Apply modeling expertise to work with
the experts interactively to build model
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Framework Data Modeling
Based on provider and consumer
requirements for GIS and mapping, focus on
a specific theme of information
Convened a group of experts with modeling
support and have them bring any relevant
systems designs or requirements documents
Built models that support a common, not
universal, set of needs
Publish model and narrative in a standard
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Common Modeling Baseline
Feature types (classes) included
Unique feature identifier system
Basic attributes
Controlled vocabulary, codes, authorities
Valid at a range of scales and resolutions
Multiple representations of same features
possible
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Feature Catalog
One first step toward developing a
conceptual model of geographic
information is to construct a Feature
Catalog
Feature Catalog includes:



Feature types, definitions
Attributes, definitions, data types
Domains, expected values and types
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Catalog as Abstract Model
Feature Catalog describes what
information is included in a given data
theme and what properties and values
are stored there
A feature catalog is not an
implementation model but can, with
rules, be used to create one or more
implementation models
Implementation guidance supplements
abstract or conceptual models
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Example UML Model
(example excerpt from the hydro model, prior to face-to-face session in November)
Dataset
describedBy
Metadata
Time of sample
POC
etc.
Metadata is at a
collection level; for
example it will apply t
o ISO, FGDC etc.
Hydrography
Permanent Feature ID
Feature Type Code
Feature Qualifier
Geometry : Geometry Type Enumeration
Source Scale Denominator : Integer
HydroLine
Reach ID
From position
To Position
Length
HydroArea
Elevation of area
Water surface basis height
Area of feature
Region ID
Feature Name
Permanent Feature ID
GNIS-ID
name
HydroPoint
ReachID
Periodicity : Periodicity Type Enumeration
Cartographic feature type code
Hydrographic feature code
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Example Tabular Description
31
Going from the Abstract to
Implementation
Conceptual modeling yields the natural
organization of the data but not a
specific implementation
For interoperability in the exchange of
data, an agreement on encoding and
format is required
CASE tools and scripts can convert UML
designs into specific implementation
schemas
32
Application Schema
Name for the rules that define the
content, relationships, attributes,
domain values and constraints in a
specific implementation environment
UML may be converted into XMI to load
the model design into a different
modeling software
UML may be converted to an XML/GML
Schema Document
33
Content + Format
Conceptual
Data
Model
Implementation
model/schema
for Format A
validation
Format A
Data
encoding
34
Creating a Standard
Data Content and Exchange Standard
Conceptual
Data
Model
Implementation
Schemas
Narrative with context,
obligation, examples
A standard facilitates interoperability if
it includes both the conceptual data
model and one or more implementation
annexes with specific guidance for
content validation
35
Framework Standard Outline
Introduction
Scope and Context
Data Content Model in
UML
Descriptive table and
narrative
Annex: Encoding using
XML (GML 3.0)
36
Geospatial Services
Increasingly geospatial data can be
accessed in real-time over local area
networks and the Internet as if it were
local data
Multiple organizations can benefit from
the data being staged and maintained
once and used many times
Desktop software and portals can use
these services over the Web
37
Framework Interoperability Pilot for
Transportation
OpenGIS Consortium (OGC) is assisting in
modeling process to define proper UML that
conforms to ISO rules and can be
implemented as GML
Contract with OGC members to implement
Web Feature Services to extend multiple
available data systems (U.S. and Canada)
Implement a Web client that can display and
query multiple Framework data sources based
on the common data model
Approach to be followed for other themes
39
Establish WFS on agreed
content nationwide
WFS
Web Feature
Browser/
Client Application
GML
(XML)
Mission
System A
translation
utilities
Native Format
Mission
System B
WFS
public
schema
P
B
private
schema
transformation
rules
40
http://www.fgdc.gov
Doug Nebert
ddnebert@usgs.gov