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ONISTT Overview

ONISTT Spatial Ontologies June 20 2006 David Martin SRI International Work done with Reg Ford, Jonathan Solnit, Mark Johnson, Daniel Elenius, Dave Hanz. ONISTT Overview. Open Net-centric Interoperability Standards for Training and Testing (ONISTT) is:

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ONISTT Overview

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  1. ONISTT Spatial OntologiesJune 20 2006David MartinSRI InternationalWork done with Reg Ford, Jonathan Solnit, Mark Johnson, Daniel Elenius, Dave Hanz

  2. ONISTT Overview • Open Net-centric Interoperability Standards for Training and Testing (ONISTT) is: • A project sponsored by Deputy Under Secretary of Defense for Readiness (DUSD/R) • Researching means to automate the composition ofimprovisational confederations of heterogeneous systems to support specific mission enactments • A fundamentalfunctionality required within such a confederation is the sharing of time-space position information (“TSPI”) • Need way to identify all possible ways a system could represent TSPI in a form that can be understood by an Inference Engine • Need ontology for spatial concepts

  3. Framing the Problem • Executing complex operations requires more capabilities than are resident within any single system • Need capability to establish a assemblage of heterogeneous systems to perform a larger task: • a System-of-Systems (SoS) • This requires achieving interoperability among the constituent systems in the SoS: Interoperability: “The ability of systems, units, or forces to provide services to and accept services from other systems, units, or forces and to use the services so exchanged to enable them to operate effectively together.” (definition from Joint Pub 1-02)

  4. Assembling A System of SystemsDeliberately Planned versus Improvisational • The traditional approach for assembling a SoS has relied on deliberately planned assemblage of cooperating systems, where • All possible member systems and their roles in the SoS, and • All required functional capabilities of the SoS, and • All Information Exchange Requirements, data formats, etc. … are identified & rigorously defined long before (typically several years before) the actual operation commences • Plus: there is some administrative body in charge of assembling the SoS which has sufficient authority to mandate changes in some (or all) of the constituent systems to achieve the goals of the SoS • Recent history of Joint and Multi-national operations have shown that the deliberately planned SoS approach does not provide adequate flexibility to support the kinds of operational capabilities that are now needed  Need a new approach that will support formation of an Improvisational assemblage of heterogeneous systems on short notice – effectively creating a SoS – but without the SoS “baggage” listed above

  5. ONISTT – How it works Capture domainknowledge TrainingSystem Web Services Interface DomainKnowledge TrainingSystem Web Services Interface Web Services Interface TrainingSystem

  6. ONISTT – How it works CreateMetadataforSystems TrainingSystem SystemsRegistry Web Services Interface DomainKnowledge TrainingSystem Web Services Interface Web Services Interface TrainingSystem

  7. ONISTT – How it works Specify Scenario Requirements TrainingSystem SystemsRegistry Web Services Interface DomainKnowledge ScenarioSpec TrainingSystem Web Services Interface Web Services Interface TrainingSystem

  8. ONISTT – How it works Generate candidate confederations TrainingSystem SystemsRegistry Web Services Interface DomainKnowledge ScenarioSpec TrainingSystem Web Services Interface Analyzer Web Services Interface Config-urationSpec TrainingSystem Role –ActorMapping

  9. ONISTT – How it works Configure systems for exercise TrainingSystem SystemsRegistry Web Services Interface DomainKnowledge ScenarioSpec TrainingSystem Web Services Interface Mediators Analyzer Web Services Interface Config-urationSpec Configurator TrainingSystem

  10. (, ) surface geodetic coordinate MP coordinate (u, v) Augmented MP coordinate (u, v, h) (, , h) 3D geodetic coordinate Augmented map projections Augmenting map coordinates with ellipsoidal height produces a 3D CS.

  11. … can be an illusion. Augmented map projections Line of sight visibility in augmented map projection coordinate space... ( u , v , w ) ( u , v , w ) 1 1 2 2 ( u , v , 0) ( u , v , 0) 1 1 2 2 coordinate -space q’ p’ position-space p q

  12. ONISTT Selection of Reference Spatial Standard • ISO-19111: Geographic information - Spatial referencing by coordinates • Used primarily for GIS applications • Existing ontologies • ISO-18026: Information Technology Spatial Reference Model • Based on SEDRIS standards • Common reference model used for modeling and simulation (M&S) and Live-Virtual-Constructive (LVC) training system applications • Specifies transforms • No existing ontology • But structure mapped naturally into an ontology framework (OWL) • A National Geospatial-Intelligence Agency (NGA) report compares 19111 and 18026 • Concludes that the scope of 18026 is much broader than 19111 and that 19111 is a subset of 18026

  13. SEDRIS SRM • The SEDRIS Spatial Reference Model (SRM) provides a precise specification of geometric properties such as position (location), direction, and distance • SRM is one of five parts of SEDRIS • Data Representation Model (DRM) • Environmental Data Coding Specification (EDCS) • Interface Specification (API) • SEDRIS Transmittal Format (STF) • SRM is codified in ISO:18026

  14. SRM Composition • Goal is to specify a spatial coordinate system in which positions can be identified • SRM accomplishes this through a spatial reference frame (SRF) • Combines an abstract coordinate system (ACS) and an object reference model (ORM) Figure taken from ISO-18026

  15. ACS and ORM • An ACS associates coordinates with positions in an abstract Euclidean space, called its position-space1 • Examples include Euclidean 3D (x-y-z) and Spherical • An ORM defines a precise relationship between a position-space and an object-space1 • Object-space is specific to the object of interest (e.g. the Earth) • Includes normal embedding, a length-preserving function between position-space and object-space • Example is the well known WGS 1984 1 – Quoted from ISO-18026

  16. Reference Datum • A Reference Datum (RD) is a geometric primitive that relates measurements and/or geometric characteristics of object-space to position-space1 • Examples are spheres or ellipsoids • ORMs use RDs to specify the position-space to object-space relationship, and to model spatial objects • An ellipsoid typically is the model for the Earth 1 – Quoted from ISO-18026

  17. Building an SRM Ontology • Separated each main idea into individual ontologies • ACS • RD • ORM • SRF Import Tree SRF ACS ORM RD

  18. Subclasses • Each of the four ontologies have subclasses defined in 18026, mostly based on number of dimensions • RD subclass “Physical” is for specific objects such as oblate ellipsoid

  19. Properties • Properties came from tables in 18026 describing the characteristics of each class • Created enumerated classes for all properties that had a known set of values

  20. Individuals • ISO:18026 specifies instances of each of the concepts • Currently our ontology only has those instances necessary to specify Geocentric WGS1984 and Geodetic WGS1984 • Also have individuals for enumerated classes

  21. Example: Geocentric WGS1984 srf:GeodeticWGS1984 srf:absCoordSys acs:Geodetic acs:csProps acs:orthogonal acs:descriptor acs:ThreeDCurvilinear acs:fcnType acs:generatingFunction srf:objRefMod orm:WGS_1984 orm:refDatumSet rd: origin3D Purple text: individual Blue text: property rd: zAxis3D rd: zPlane3D

  22. Future Work • The current ontology is not a complete specification of ISO:18026 • Possible additions include: • Coordinate system transformations • Includes identifying the properties that are preserved or not when transforming from one coordinate system to another • Temporal coordinate systems • Vertical offset surfaces • “Generating functions” for abstract coordinate systems • Binding constraints for ORMs • Filling in the rest of the individuals

  23. Other ONISTT Spatial Ontologies • Because few standard domain ontologies currently exist, the ONISTT team developed some preliminary (temporary) custom ontologies for small subsets of fundamental domains • Spatial ontologies • ISO-18026 ontology provides spatial reference frame property for entity positions • Positional component properties: EngineeringValue and EngineeringMeasurement • Time-Space Position Information (TSPI) ontology adds time to positional information • Time ontology extends daml/time-entry • Example ONISTT application of spatial ontologies • Describe inputs, outputs, quality characteristics for service ontologies • nexri/tspi-report ontology completely describes the contents of a message, from semantics to bit representation

  24. ONISTT Time Space Position Information (TSPI)Import Tree

  25. ONISTT Engineering Value Ontology • EngineeringValue class • Properties: magnitude and unitOfMeasure (EngineeringUnit) • Subclasses for Length, Angle, Quaternion, etc. • EngineeringUnit class • Subclasses for LengthUnit, AngleUnit, etc. • Property siUnit identifies the standard unit for each unit class • Property siUnitConversionFactor identifies the conversion from each subclass individual to the standard unit • E.g., for the AreaUnit acre individual, the siUnitConversionFactor to the siUnit (square-meter) is 4.046873E+03

  26. ONISTT Engineering Measurement Ontology • Adds concept of measurement uncertainty to Engineering Value • EngineeringMeasurement class • Subclasses for LengthMeasurement, AngleMeasurement, etc • Property measurand is an EngineeringValue • E.g., the measurand value for LengthMeasure subclass is restricted to the Length class of EngineeringValue • Property uncertaintyType is Uncertainty class • Property uncertaintyValue is EngineeringValue type (restricted as appropriate for the subclass) or FractionalUncertainty type • Uncertainty class • Property estimateType is UncertaintyEstimateType class, with individuals CEP, SEP, etc. • Property distributionType is UncertaintyDistributionType class, with individuals Gaussian, Poisson, Rayleigh, etc.

  27. ONISTT Time Ontology • ONISTT extended damltime/time-entry.owl (by Feng Pan and Jerry Hobbs) to provide to M&S timestamps, adding the following classes: • Granularity – smallest distance between two instants supported • Reference – starting point of a time standard, e.g. midnight January 1, 1970 • Rollover – when a time resets to 0 (to avoid overflow of a limited size time field) • Timefield – class with object properties to use the first three, plus datatype properties for the timefield size in bits and time value • Time value is a TimeInstant EngineeringMeasurement (including units and uncertainty estimate) • Timestamp – class with an object property specifying one or more Timefields • Allows unambiguous specification of the various M&S time formats encountered by the ONISTT program

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