Geospatial Semantic Web:
Is there life after
geo:lat and geo:long ?
Joshua Lieberman
Traverse Technologies & Open Geospatial Consortium
European Geoinformatics Workshop, March 2007
jlieberman@traversetechnologies.com
What’s the (Geo) Problem?
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Special spatial
What is geospatial interoperability?
semantic Web - microformat tagging and (multiple) identity
Semantic Web - (actionable) relationships and triple identity
geosemantic - geotagging position
Geosemantic - spatial(-temporal) theories, relationships,
mediations, transformations
• Feature (type) and Geometry (representation)
• Model dependencies
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Community of discourse
Scale
Reference frame / coordinate system
Perspective
• Geospatial plus other (semantic) dimensions
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 2
Background
• My context - earth / environmental sciences -> data
manager -> Web 1.0 victim -> geospatial standards geek
• What is the geospatial problem, anyway? Is it a
geospatial problem? Who needs interoperability?
• Playing fields and players, an arbitrary list:
– Open Geospatial Consortium
– Worldwide Web Consortium
– SOCoP
• “Standards are great, there are so many to choose from”
• “OGC is full of semantics, we just don’t let much of it leak
out”
• “If there is artificial intelligence, does that mean there is
also artificial stupidity?”
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 3
Geospatial Semantic Web Challenge:
Interoperability
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The Geospatial part
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The Web part
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Accessibility of “secret” knowledge
Interoperability between communities and domains
Softer software
Automated (machine to machine) reasoning and inference
The Geosemantic part
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Distributed data - “own and maintain locally / find and access globally”
Shared services, loosely or tightly coupled to geodata
Interoperability between technologies, vendors, architectures
The Semantic part
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Maps and map visualization
Features and feature geometries
Geographic and other relationships
Coordinate and other reference systems
Feature discernment
Spatial reasoning
Representational dissonance
No particular part
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Cognitive dissonance
Context and viewpoint
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 4
What are OGC and OWS ?
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“The
Open Geospatial Consortium, Inc. (OGC) is a non-profit, international, voluntary consensus
standards organization that is leading the development of standards for geospatial and location based
services”
“Opengeospatial Web Services” (OWS) - OGC has been developing for some time specifications for a
suite of Web services (sensu latu) and associated encodings to expose geospatial content and
operations from distributed content repositories to remote clients across diverse platforms:
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GML - geographic markup language (an information model and XML schema) for encoding features
(geometric representations of geography).
Web Feature Service - service providing access to collections of features
Web Map Service - service providing access to map layers (cartographically rendered features and
images)
Catalog Service / Web - service supporting (spatial) discovery of geospatial datasets and services
Several other associated specifications, e.g. coordinate reference system encoding
Many corresponding or related ISO standards, especially 191nn (TC211)
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 5
General Feature Model
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 6
Interoperability Stack
Increasing / higher level interoperability
Human-centric
• Meaning - ? (OWL, RDF, MDL, …)
• Vocabulary – UML, XML Schema, OWS
• Encoding - ASCII, UTF-8, XML
• Control – TCP, HTTP, WAP
• Signal – Internet Protocol, DNS
• Transport – Ethernet, WiFi, GPRS
• Medium – Physical Connection
Machine-centric
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 7
Geospatial R/Evolution
• Geospatial Semantic Web: forming and
distributing rich geospatial relationships
across the Web
• GeoRSS: adding features to information
• Google Earth: the terrain as video game
• GeoWeb: connecting features across the
Web
• GIS: adding information to features
Cartography: symbolic representation of
the terrain
• Geography: perception of the terrain
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 8
Which Geospatial Role?
Upper Ontologies?
Geographic Infromation System
Tasks / Processes
Interpret
Visualize
Model
Common Geospatial Perspective
Collect
Petro
Aero
Hydro
Weather
Solar
Base
Ontologies?
Geo
Information Domains
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 9
Use cases and roles
for semantic Web processing
• Cross-domain resource discovery
• Heterogeneous resource query
• Resource translation
Trader
Client
Server(s)
Broker
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 10
“Typical” Geospatial Query
(Intelligence / Logistics Domain)
“Which airfields within 500 miles of Kandahar support C5A aircraft?”
Feature
property or
non-spatial
information?
Aero Feature or
Geo Feature?
Buffer or
proximity?
What does this
mean to a GIS ?
Statutory or Nautical?
Straight-line or driving?
Coordinate system?
Afghanistan?
Centroid or outline?
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 11
Multiple GSW Ontology Components
Other Upper Ontologies
OGC Upper
Ontology
(e.g. Feature)
GeoIntel
Problem Domain
Ontology
Aero Feature
Ontologies
(AIXM, DAFIF)
Base Geospatial Ontology
(e.g. filter encoding)
Other Base Ontologies (e.g. measurements)
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 12
Ontologies for Enhanced GI Discovery
Which airfields within 80
miles of Banda Aceh support
C5A aircraft, i.e. have a
runway length >= 12000 ft?
Ontological (DL) description of
the query concept
Hybrid Ontology Approach
Query concept
based on
Logical equivalence or
subsumption
Reasoning
based on
Application Ontology
Concept
John Smith
Domain
Ontology
Ontological (DL) description of the application concept “Dafif_Airport”
ID Name
1 Greenville
2 Festus Mem
Airp_Ident
US01357
US05536
ICAO Elev
KZ
00541
KZ
00433
Type
A
A
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 13
OWL-S Service Description
Components and Questions
Type of Service
Themes of Content
Service Profile
Provider / business terms
Content Description
Service Bindings / Messages
Feature Schema
Service Grounding
Content Domain
Bound Parameters
Feature Individuals
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Process and Behavior
Smart Service Consumption
Service Model
Service Composition
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 14
GSW IE and Beyond
• The OGC geospatial semantic web interoperability experiment tested
initial architectures and technologies for cross-domain, distributed
geospatial knowledge query, leading to multiple follow-on activities.
Geospatial Intelligence Query:
“Which airfields within 500 miles of
Kandahar support C5A aircraft”
GeoRSS geospatially enabled
resource references
Query Domain
Ontology
Geospatial Ontologies workshops
(resource, process, service)
OWL-S
Description
DAFIF
Ontology
OWL-S
Description
AIXM
Ontology
OWL-S
Description
Gazetteer
Ontology
Aero Data
(DAFIF) WFS
Aero Data
(AIXM) WFS
Geonames
Data Gazetteer
Service
W3C Geospatial
Semantic Activities
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 15
A Theory of One’s Own
• Classical Scientific Method:
– Observation -> Hypothesis -> Test
• SWE:
– Procedure -> Sensor -> Measurement -> Observation ->
Hypothesis
• John Wesley Powell:
– Multiple Hypothesis -> Observation -> Selection
• Practical / Tenure track
– Theory -> Procedure -> Measurement -> Observation ->
Publication
• In “reality” observations are always predicated upon a
theory, although they may subsequently induce theory
revision.
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 16
Problems of heterogeneity
• Semantics: two names for the same thing
• Semiotics: one name for two different things
• Schizophrenia (cognitive dissonance): two names for two
different things
Vertical Obstruction
Lighthouse
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 17
Semantic quandaries
• Two co-located shapes -> “semantic heterogeneity”
• Agree “obstruction” equals “lighthouse” -> boat crashes
into a water tower
• Agree lighthouse “is a” vertical obstruction -> ship
ignores light buoy, hits shoal
• Agree vertical obstruction “is a” lighthouse -> plane hits
watertower
• We have “cognitive heterogeneity” -> two theories for the
same reality
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 18
Unsettling Solutions
• Possible solution: intersect theories -> lighthouse and vertical
obstruction are both “elevations”, but little may be agreed on the role
or behavior of that shared reality. Semantic technology provides few
tools to distinguish the “theories” of the subclasses.
Elevation
Aero Hazard
Marine
Navigation Aid
Vertical Obstruction
Lighthouse
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 19
Top of the Interoperability Stack
Increasing / higher level interoperability
Human-centric
• Purpose – Enlightenment, tenure
• Perception – Visual - aural - tactile
• Theory - persistence, consequence
• Discernment – Feature, context
• Application – Discovery, analysis, profit
• Representation– geometry, equation
• Ontology – domain, upper, lower
Machine-centric
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 20
W3C Geo XG
• W3C Geospatial Incubator is a new type of activity for short-term
and/or startup goals
• The (proposed) Geo XG has three objectives which address needs
of the Local Web:
– Immediate: update and harmonization with GeoRSS of the W3C Basic
Geo vocabulary, aka simpler than possible geospatial ontology.
– Short Term: draft recommendations for a geospatial ontology focused on
Web resources and tasks.
– Longer Term: draft a charter for a proposed W3C Local Web WG and/or
IG to address issues beginning with geotags and continuing towards
geospatial enablement of the Semantic Web.
• Largely open to public participation
• Chartered until June 2007
• http://www.w3.org/2005//Incubator/geo/
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 21
W3C 2003 Geo Vocabulary
• Devised and posted by Dan
Brickley (danbri)
• Not a Note or
Recommendation
• Separate latitude & longitude
properties, presumes WGS 84
• Implies a point “feature” and
single position.
• Makes no other assertion as to
the meaning of the coordinates
or their relationship to the item
or resource they characterize.
• Geo:lat and geo:long are also
used for geotagging other
content (e.g. XHTML
microformats).
The vocabulary defines a class 'Point', whose members are
points. Points can be described using the 'lat' and 'long'
properties.
<geo:Point>
<geo:lat>55.701</geo:lat>
<geo:long>12.552</geo:long>
</geo:Point>
In common usage, the containing Point is dropped, for
brevity.
<?xml version="1.0"?>
<rss version="2.0"
xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#"
>
<channel>
...
<item>
<title>An example annotation</title>
<link>http://example.com/geo</link>
<description>Just an example</description>
<geo:lat>26.58</geo:lat>
<geo:long>-97.83</geo:long>
</item>
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 22
GeoRSS 1.0 Content “Featurizing” Model
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 23
GeoRSS Examples
• Simple
• GML
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<georss:where>
<gml:Point>
<gml:pos>45.256 -71.92</gml:pos>
</gml:Point>
</georss:where>
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<georss:where>
<gml:Polygon>
<gml:exterior>
<gml:LinearRing>
<gml:posList>
45.256 -110.45 46.46 -109.48 43.84 109.86 45.256 -110.45
</gml:posList>
</gml:LinearRing>
</gml:exterior>
</gml:Polygon>
</georss:where>
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<georss:point>45.256 -71.92</georss:point>
<georss:line>45.256 -110.45 46.46 -109.48
43.84 -109.86</georss:line>
<georss:polygon>
45.256 -110.45 46.46 -109.48 43.84 109.86 45.256 -110.45
</georss:polygon>
<georss:box>42.943 -71.032 43.039 69.856</georss:box>
<georss:featuretyeptag>city</georss:featuretyp
etag>
<georss:relationshiptag>is-containedwithin</georss:relationshiptag>
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GeoRSS Simple maps directly onto GeoRSS GML !
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 24
SOCoP:
Spatial Ontology Community of Practice
• SOCoP is chartered as a Community of Practice under the Best Practices
Committee of the Federal CIO Council.
• Charter: The strict purpose and focus of the Spatial Ontology Community of
Practice (SOCoP) is to foster collaboration among researchers, technologists &
users of spatial knowledge representations and reasoning towards the
development of a set of core, common spatial ontologies for use by all in the
Semantic Web. As a Community of Practice SOCoP using open collaboration
and open standards, SOCoP developed ontologies will offer increased
interoperability of spatial data across government (via synchronization with
Geospatial Profile of FEA & GeoLOB) as well as across the entire spectrum of
the World Wide Web (via W3C, ISO, OGC, etc.). SOCoP represents a strategic
investment for ontology development, building on core ontological
competencies, documenting best practices, and creating opportunities to partner
with other cross domain and ontology COP groups. Among other things SOCoP
can help inventory geospatial ontologies, develop an approach to
institutionalizing and streamline the effort to support the development and
management of ontologies across the GeoLOB.
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 25
Geospatial Semantic Web Standards (?)
• Geospatial Ontologies
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Neogeo / GeoRSS
Feature metamodel
Feature types
Geonames / toponymology
Spatial relationships
Coordinate reference systems
• Geospatial Discovery
– Indexing vs modeling
– GeoRSS: geographic
assertions over resources
– GRL: Geo resource locator
– GREF: Geo reference
– GNS: Geo Name Server
• Geosemantic Reasoning
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Geospatial subsumption
Processing spatial relationships
Geospatial rules
(Geo) SPARQL ?
Visual reasoning - map and reality
• Geospatial Semantic Web
Services
– (Does) content matter?
– Transformation services
– Mediation (semiotic, semantic,
cognitive) and client
perspective
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 26
Geospatial Semantic Convergence
• When geography-on-demand joins knowledge-with-location, the result
will be a richer and more capable Web of physical resources, a
Geospatial Semantic Web or Local Web having identity, connection,
and locality
GIS Guilds
Geographic representation
standards
Geospatial Web
Geospatial Web services
architecture standards
Geospatial Enablement
Local
Geospatial enablement of
enterprise information
Semantic enablement of the
World Wide Web
Information Silos
Resource relationship
standards
Resource identifier and
transport standards
Web of
Knowledge
Web
Semantic
Web
Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies.
Slide 27
What do you see is next?