Community semantics and interoperability: the ISO/TC 211 framework and the “Hollow World” Simon Cox CSIRO Exploration and Mining 6 September 2005

Application schema Outline ISO framework for community application schemas Example of process & product in geoscience Some issues

Application schema Premise: communication occurs within communities Successful information transfer occurs when parties share a common language This also applies to transfer of technical data How much is “common”?  Concepts  Models and structures  Vocabularies  Encodings

Application schema Developing a community language Two purposes: 1.Common understanding of a particular application field. 2.Create schema for data management. Stepwise process: 1.Survey requirements from field of application (Universe of Discourse). 2.Identify feature types, their properties and constraints. 3.Describe application schema in a formal modelling language. 4.Integrate formal application schema with other standardized schemas, (spatial schema, quality schema, etc.) ISO Geographic Information – Rules for Application Schema

Application schema Domain-specific feature types - geology Borehole  collar location  shape  collar diameter  length  operator  logs  related observations  … Fault  shape  surface trace  displacement  age  … Ore-body  commodity  deposit type  host formation  shape  resource estimate  … Observation  time  target/location  property  procedure + operator  result  … Conceptual classification Multiple geometries License area  issuer  holder  interestedParty  shape(t)  right(t)  … “Natural” features Constructed artefacts Artefacts of investigation

Application schema Structure of a feature-type

Application schema Relationships between feature types

Application schema ISO/TC 211- Implementation – conceptual schema language  Profile of UML – encoding rules (UML  XML) – Geography Markup Language  WXS implementation of Features, Geometry, Temporal, CRS

Application schema Modelling methodology 1.Get key community representatives engaged

Application schema IUGS-CGI “Model and encoding task group” 2003 November – BGS Edinburgh  28 people from 15 geological surveys 2004 April – GSC Ottawa  4 people from USGS, GSC, CSIRO 2004 December – CSIRO Perth  11 from USGS, AZGS, GSC, BGS, GSJ, GSV, GSWA, GSNSW, CSIRO 2005 August – GSC Ottawa  8 from: USGS, AZGS, GSC, BGS, GSV, CSIRO

Application schema Modelling methodology 1.Get key community representatives engaged 2.Design using UML class diagrams  use “Hollow World” UML template  includes selection of ISO, OGC and SEE Grid models  implements ISO profile of UML i.e. compatible with GML meta-model & mapping rules

Application schema Hollow-world in UML IDE

Application schema Modelling methodology 1.Get key community representatives engaged 2.Design using UML class diagrams  use “Hollow World” UML template  includes selection of ISO, OGC and SEE Grid models  implements ISO profile of UML i.e. compatible with GML meta-model & mapping rules 3.Use hand-coded sample instance documents to test model – iterate

Application schema Serialization for transfer Specimen test instance Specimen test 1 … chips 0.35 …

Application schema Modelling methodology 1.Get key community representatives engaged 2.Design using UML class diagrams  use “Hollow World” UML template  includes selection of ISO, OGC and SEE Grid models  implements ISO profile of UML i.e. compatible with GML meta-model & mapping rules 3.Use hand-coded sample instance documents to test model – iterate 4.Link with utility and related packages

Application schema GeoSciML – package dependencies

Application schema ISO/TC 211- Standard models and components – coverage schema  continuous data, grids – spatial schema  geometry & topology – coordinates & reference systems  influenced by EPSG/POSC – temporal schema  temporal objects and reference systems – moving-features schema UML class models

Application schema GML Assembling an application schema - GeoSciML O&M/XMML NADM GSV

Application schema Modelling methodology 1.Get key community representatives engaged 2.Design using UML class diagrams  use “Hollow World” UML template  includes selection of ISO, OGC and SEE Grid models  implements ISO profile of UML i.e. compatible with GML meta-model & mapping rules 3.Use hand-coded sample instance documents to test model – iterate 4.Link with utility and related packages 5.Generate XML Schema (GML Application Schema) either  by hand following UML2GMLAS rules or  from XMI using ShapeChange application … “Model Driven Architecture” 6.Publish model and service profiles  Feature-type catalogue  UML/XMI, XML Schema, OWL?, ISO 19126??  Registry …

Application schema Issues: observational data Scientific data is different … Property values are often estimated, not assigned  observation procedures and uncertainty  “property-level” metadata mostly

Application schema Package of feature types for observational data

Application schema Issues: property values You ain’t finished yet … structure is not enough  scales, units of measure required for numeric values  vocabularies/lexicons required for category values  definitions may refer to prototype or exemplar feature instances …

Application schema Issues: registration and governance Users must have access to language definition, in order to use data and services  feature-types and lexicons must be registered  community must use an orderly governance process ISO 19135: Procedures for Registration of Items of Geographic Information

Application schema ISO/TC 211- Governance – feature model – feature cataloging  … a community vocabulary – data dictionary registers and feature catalogue registers – Procedures for registration of items  governance principles – dataset metadata – service metadata

Application schema Summary ISO provides framework for developing application language for geospatial communities  methodology  standard components Elements:  Concepts – feature-catalogue  Models and structures – UML application schema  Vocabularies – ontologies?  Encodings – GML application schema

Application schema More info SEE Grid TWiki  Standards framework for geospatial information  Information models and community languages  UML & GML  

Thank You CSIRO Exploration and Mining NameSimon Cox TitleResearch Scientist Phone Webwww.seegrid.csiro.au Contact CSIRO Phone Webwww.csiro.au

Application schema Application schemas build on common components

Application schema Open Geospatial Consortium Primarily a vendor consortium, Implementation specifications  Service interfaces  Data encodings Interoperability projects

Application schema From discourse to data

Application schema OGC - Service interfaces (selection) Web Map Service  Fixed resolution maps (styled) Web Feature Services  Fine-grained data access – object-oriented Web Coverage Service  Access to continuous data Catalogue Service  Data/service discovery – metadata Sensor Web  live data, tasking and scheduling  adapt for simulation services

Application schema OGC Services

Application schema OGC - Information standards & profiles Geography Markup Language Observations and Measurements Core catalogue record Map context  state, data product Styled-layer descriptor Gazetteer profile for WFS  GML implementation of ISO XLS for Location-based-services

Application schema Four layer model