Geospatial Semantic Web: Is there life after geo:lat and geo:long ? Joshua Lieberman Traverse Technologies & Open Geospatial Consortium European Geoinformatics

Geospatial Semantic Web:Geospatial Semantic Web:Is there life after Is there life after

geo:lat and geo:long ?geo:lat and geo:long ?Joshua Lieberman

Traverse Technologies & Open Geospatial Consortium

European Geoinformatics Workshop, March 2007

[email protected]

Joshua Lieberman - European Geoinformatics Workshop 2007 ©Traverse Technologies. Slide 2

What’s the (Geo) Problem?What’s the (Geo) Problem?

• 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

– Community of discourse– Scale– Reference frame / coordinate system– Perspective

• Geospatial plus other (semantic) dimensions


BackgroundBackground

• 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?”


Geospatial Semantic Web Challenge: Geospatial Semantic Web Challenge: Interoperability Interoperability

• The Geospatial part– Maps and map visualization– Features and feature geometries– Geographic and other relationships– Coordinate and other reference systems

• The Web part– 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– Accessibility of “secret” knowledge– Interoperability between communities and domains– Softer software– Automated (machine to machine) reasoning and inference

• The Geosemantic part– Feature discernment– Spatial reasoning– Representational dissonance

• No particular part– Cognitive dissonance– Context and viewpoint


What are OGC and OWS ?What are OGC and OWS ?

• “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:

– 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)


General Feature ModelGeneral Feature Model


Interoperability StackInteroperability Stack

• 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

Increasing / higher level interoperability

Human-centric

Machine-centric


Geospatial R/EvolutionGeospatial 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


Which Geospatial Role?Which Geospatial Role?Tasks /

Pro

cesses

Information Domains

Petro Aero GeoHydro Weather Solar

Collect

Model

Interpret

Visualize

Geog

rap

hic

In

from

ati

on

Syste

m

Common Geospatial Perspective

Upper Ontologies?

Base Ontologies?


Use cases and roles Use cases and roles for semantic Web processingfor semantic Web processing

• Cross-domain resource discovery• Heterogeneous resource query• Resource translation

Find

Provi

sion

Publish

Order

BindClient Server(s)

Trader

Broker


““Typical” Geospatial Query Typical” Geospatial Query (Intelligence / Logistics Domain)(Intelligence / Logistics Domain)

“Which airfields within 500 miles of Kandahar support C5A aircraft?”

Aero Feature or Geo Feature?

Buffer or proximity?

Statutory or Nautical?Straight-line or driving?Coordinate system? Afghanistan?

Centroid or outline?

What does this mean to a GIS ?

Feature property or non-spatial information?


Multiple GSW Ontology ComponentsMultiple GSW Ontology Components

GeoIntelProblem Domain

Ontology

Base Geospatial Ontology(e.g. filter encoding)

Aero Feature Ontologies

(AIXM, DAFIF)

OGC Upper Ontology

(e.g. Feature)

Other Base Ontologies (e.g. measurements)

Other Upper Ontologies


Which airfields within 80 miles of Banda Aceh support C5A aircraft, i.e. have a runway length >= 12000 ft?

equivalence or subsumption

based on

based on Domain Ontology

Ontological (DL) description of the query concept

Query concept

ID Name Airp_Ident ICAO Elev Type1 Greenville US01357 KZ 00541 A2 Festus Mem US05536 KZ 00433 A

Ontological (DL) description of the application concept “Dafif_Airport”

Application Ontology ConceptJohn Smith

Hybrid Ontology Approach

Logical Reasoning

Ontologies for Enhanced GI DiscoveryOntologies for Enhanced GI Discovery


OWL-S Service Description OWL-S Service Description Components and QuestionsComponents and Questions

Type of Service

Themes of Content

Provider / business terms

Content Description

Service Bindings / Messages

Bound Parameters

Process and Behavior

Smart Service Consumption

Service Composition

Service Profile

Service Grounding

Service Model

Feature Schema

Content Domain

Feature Individuals

?


GeoRSS geospatially enabled resource references

Geospatial Ontologies workshops(resource, process, service)

W3C Geospatial Semantic Activities

GSW IE and BeyondGSW 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.

Aero Data (DAFIF) WFS

Aero Data (AIXM) WFS

Geonames Data Gazetteer

Service

DAFIF Ontology

AIXMOntology

GazetteerOntology

Query Domain Ontology

OWL-SDescription

OWL-SDescription

OWL-SDescription

Geospatial Intelligence Query:“Which airfields within 500 miles of

Kandahar support C5A aircraft”


A Theory of One’s OwnA 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.


Problems of heterogeneityProblems 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

LighthouseVertical Obstruction


Semantic quandariesSemantic 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


Unsettling SolutionsUnsettling 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.

Vertical Obstruction

Elevation

Lighthouse

Marine Navigation Aid

Aero Hazard


Top of the Interoperability StackTop of the Interoperability Stack

• Purpose – Enlightenment, tenure

• Perception – Visual - aural - tactile

• Theory - persistence, consequence

• Discernment – Feature, context

• Application – Discovery, analysis, profit

• Representation– geometry, equation

• Ontology – domain, upper, lower

Increasing / higher level interoperability

Human-centric

Machine-centric


W3C Geo XGW3C 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/


W3C 2003 Geo VocabularyW3C 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>


GeoRSS 1.0 Content “Featurizing” ModelGeoRSS 1.0 Content “Featurizing” Model


GeoRSS ExamplesGeoRSS Examples

• Simple• <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:featuretypetag><georss:relationshiptag>is-contained-within</georss:relationshiptag>

• GML• <georss:where>• <gml:Point>• <gml:pos>45.256

-71.92</gml:pos>• </gml:Point>• </georss:where>

• <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>

GeoRSS Simple maps directly onto GeoRSS GML !


SOCoP: SOCoP: Spatial Ontology Community of PracticeSpatial 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.


Geospatial Semantic Web Standards (?)Geospatial Semantic Web Standards (?)

• Geospatial Ontologies– Neogeo / GeoRSS– Feature metamodel– Feature types– Geonames / toponymology– Spatial relationships– Coordinate reference systems

• Geospatial Semantic Web Services– (Does) content matter?

– Transformation services

– Mediation (semiotic, semantic, cognitive) and client perspective

• Geosemantic Reasoning– Geospatial subsumption

– Processing spatial relationships

– Geospatial rules

– (Geo) SPARQL ?

– Visual reasoning - map and reality

• Geospatial Discovery– Indexing vs modeling

– GeoRSS: geographic assertions over resources

– GRL: Geo resource locator

– GREF: Geo reference

– GNS: Geo Name Server


Geospatial Semantic ConvergenceGeospatial 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

Local

Web

Geographic representation standards

Geospatial Web services architecture standards

Geospatial enablement of enterprise information

Resource identifier and transport standards

Resource relationship standards

Semantic enablement of the World Wide Web

Semantic Web

Web of Knowledge

Information Silos

GIS Guilds Geospatial WebGeospatial Enablement

What do you see is next?What do you see is next?

Documents

Geospatial Semantic Web: Is there life after geo:lat and geo:long ? Joshua Lieberman Traverse Technologies & Open Geospatial Consortium European Geoinformatics