Smart Maps and Dumb Questions: A Geospatial Semantic Web Interoperability Experiment Joshua Lieberman Traverse Technologies, Inc. & Northrop Grumman Information Technology / TASC

© 2004 Traverse Technologies Inc. Background  Geospatial Semantic Web : Use of Semantic Web technologies to discover and reason on geospatial information (UCGIS, Egonhofer, Sheth, etc.)  GSW broad research activity sponsored by National Geospatial Intelligence Agency (NGA), undertaken by a number of investigators  Interoperability experiment : an Open Geospatial Consortium(OGC) - sanctioned member collaboration to test or refine OGC specifications  This “ GSW IE ”: activity proposed by NGA, NGIT/TASC, and BBN to test and refine OGC(+) specifications within a scenario for geospatial query with formal semantics:  Web Feature Service (WFS) and Filter Encoding (FE)  Geographic Markup Language (GML)  ISO / / 1910n / FGDC feature metadata (ISO)

© 2004 Traverse Technologies Inc. Drilling Down:  The Geospatial part  Maps and map visualization  Features and feature geometries  Geographic and other relationships  The Web part  Distributed data - “maintain locally / access globally”  Shared services, loosely or tightly coupled to geodata  Interoperability between technologies, vendors, architectures  The Semantic part  Interoperability between communities and domains  Softer software  Automated reasoning and inference

© 2004 Traverse Technologies Inc. Goals of this experiment  Exercise current semantic technology in a geospatial domain  End-to-end geospatial semantic query  Utilize multiple ontologies for Geointel operations  Develop OGC service descriptions with formal semantics (OWL-S)  Develop and test Semantic Web Services interface / role for OGC services  Enhance interoperability in a distributed, heterogeneous world

© 2004 Traverse Technologies Inc. The Web Changes Everything  Global communities for local geography  Distributed information networks  Premium on interoperability  The GIS dialtone  Maintain locally, access globally  Currency is the currency  (non-GIS) barbarians are at the (GIS) gate

© 2004 Traverse Technologies Inc. Role of interoperability  Focuses on sustained operability - today and the next day  Permits separation of concerns  Supports information portability  Allows component interchangeability  Contributes to transparency, testability, and trust  Layers of interoperability build on one another  Stable syntax promotes shared semantics / understanding  Standards are necessary but not sufficient for interoperability

© 2004 Traverse Technologies Inc. Interoperability 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 interoperability Human-centric Machine-centric

© 2004 Traverse Technologies Inc. Geospatial Reasoning: 2-D and Beyond  Coordinate relationships  Scale significance  Coordinate reference systems  Topological relationships  Network  Overlay  Spatial inference  Proximity  Continuity  Representation  Dimensionality  Temporality

© 2004 Traverse Technologies Inc. “Typical” GeoIntel Query: “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? Feature property or non-spatial information?

© 2004 Traverse Technologies Inc. Sequence of Experiments Link Ontologies into Knowledgebase Generate and Visualize OWS (WFS) Queries Request Remote Service Descriptions Process Queries Through Knowledgebase Compose Queries and Query Templates Generate and Distribute Sub-queries Identify and Build Ontologies for Geospatial / GeoIntel Domains

© 2004 Traverse Technologies Inc. GSW Ontology Components GeoIntel Problem Domain Ontology “Upper” Geospatial Ontology NGA Feature Ontology OGC Services Ontology Other “Upper” Ontologies

© 2004 Traverse Technologies Inc. Model Query Sequence Question Template Query Rules Knowledge Base Reasoning & Inference Domain Ontology Ontologies Remote WFS Get Feature Local Ontologies Visualizer Map Knowledge Server Knowledge Server Sub-query Service Request Query Client Visualization Client

© 2004 Traverse Technologies Inc. OWL-S Service Description Components Type of Service Themes of Content Provider / business terms Content Description Service Bindings / Messages Bound Parameters Service Quality Smart Service Consumption Service Composition Service Profile Service Grounding Service Model Feature Schema Content Domain Feature Individuals ?

© 2004 Traverse Technologies Inc. Proposed (Interoperability) Experiments Experiment #1: Construct a feature dataset ontology (for the GEOINT domain) using OWL in order to describe 5-6 sample feature collections. Experiment #2: Construct an OWS service description ontology using OWL-S in order to describe WFS services. Experiment #3: Translate realistic GEOINT request into a semantic query language encoding (requires additional geospatial and problem domain ontologies). Experiment #4: Perform an end-to-end geospatial semantic query in a non-distributed environment using the results of Experiment #1-Experiment #3; the result of this query process will be WFS service requests for information which satisfies the query. Experiment #5: Implement and test an OWS capabilities type and/or interface which returns service / content descriptions such as in Experiment #1 and Experiment #2 from WFS service instances. Experiment #6: Perform an end-to-end geospatial semantic query as in Experiment #4 but involving remote requests for metadata as in Experiment #5.

© 2004 Traverse Technologies Inc. This Road Ahead  More and further  Geo-semantic Catalogs (c.f. OWS-3)  Semantic Service-oriented Architectures  Knowledge Services  Fine-grained, dynamically composable geoservices  Your Ideas