Session 1: Introduction to Geospatial Standards • Why do we care about standards? • Agreement on syntax, information models and interfaces lets us share information and processes. – Often not for technical brilliance (although sometimes) – For consensus and agreement
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Session 1: Introduction to Geospatial Standards Why do we care about standards? Agreement on syntax, information models and interfaces lets us share information.
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Session 1: Introduction to Geospatial Standards
• Why do we care about standards?• Agreement on syntax, information models and
interfaces lets us share information and processes.– Often not for technical brilliance (although sometimes)– For consensus and agreement
Relevant Standards Bodies: ISO/TC 211
• Technical Committee of the International Organisation for Standardisation.
• ISO is a non-governmental organisation with members in each country.
• Responsible for the geographic information series of standards.
• http://www.isotc211.org/
• Important standards for metadata (Session 2) and many others.
• World Wide Web Consortium.• International community for standards related to the web.• http://www.w3.org/• Core web standards (HTML, HTTP, XHTML, SOAP).• XML related standards (XML, XML Schema, XSLT,
XQuery).• Semantic standards (RDF, OWL, SPARQL, SKOS).• Not geospatial, but used and extended in many geospatial
standards.
Relevant Standards Bodies: OASIS
• Organisation for the Advancement of Structured Information Standards.
• International Consortium developing open standards for the global information society.
• http://www.oasis-open.org/home/index.php• Many standards relating to interoperability.• ebRIM, ebRSS.• Not geospatial, but used by some geospatial standards.
Relevant Standards Bodies: The Open Geospatial
Consortium• An international consortium of universities, private companies,
government agencies.
• Develops standards for geospatial and location based services.
• http://www.opengeospatial.org/
• Most important body for geospatial information.
• Uses and adapts standards from other groups where possible.
• Meets quarterly (in Sydney this December)
The OGC Standards Framework
• Abstract Specifications.• OpenGIS Standards.• OpenGIS Reference Model.• Best Practices Documents.• Discussion Papers.• White Papers.• OGC Interoperability Experiments.
OGC Abstract Specifications
• Platform independent abstract model.• Reference model for the development of OGC
standards.• Many become ISO/TC 211 Standards.
OGC Standards Process
Discussion PaperDiscussion Paper
Best Practices Document
Best Practices Document
SpecificationSpecification
Acceptance by Working Group Vote at TC Meeting
Acceptance by full plenary at TC Meeting or eVote(>=2 implementations)
Catalogue Services SpecificationAccess to catalogue information.Multiple profiles, extension packages, discussion papers and best practice documents.
Simple FeaturesCommon architecture and interfaces for access to geographic data with OLE/COM, CORBA and SQL.
Coordinate Transformation ServiceStandard way to specify and access and coordinate transformation services.
Web Coverage ServiceRetrieval of geospatial data as coverages (space varying phenomena).
Filter EncodingXML encoding for filter expressions
Web Coverage Processing ServiceDefines a language for retrieval and processing of multi-dimensional geospatial coverages representing sensor, image, or statistics data.
Geographic ObjectsA set of abstractions for describing, rendering, and manipulating geographic objects
Web Feature ServiceRetrieval of geographic object-based features.
Grid Coverage Service (Retired)Raster analysis and processing.
Web MapServiceGeneration and retrieval of geo-registered map images.
Open Location Services (OpenLS)Interfaces for Location Based Applications.
Web Processing ServiceRules for inputs and outputs from geospatial processing services.
Sensor Observation ServiceAPI for deploying sensors and retrieving sensor data.
Web Service CommonParameters and structures that are common to all OGC web service standards.
Sensor Planning ServiceInterface for sensor querying.
OpenGIS Encoding Standards
CityGMLVirtual 3D city and landscape models.
Observations and MeasurementsAbstract model and XML Schema for Observations.
Geography Markup LanguageXML grammar for geographic features.
Sensor Model LanguageModels and XML encoding for sensors and sensor systems.
Geospatial eXtensible Access Control Markup Language (GeoXACML)
Styled Layer DescriptorSymobolization and colouring of geographic features in WMS.
GML in JPEG 2000Using GML with JPEG for geographic imagery.
Symbology Encoding
KML Transducer Markup LanguageExchange of data with sensors.
OGC Interoperability Experiments
• Projects set up by the OGC.• Parties are invited to participate.• No financial incentive usually.• Allow you to get involved with other groups
testing standards.
OGC Web Service Basics• Set of methods or operations with:
– A set of defined request parameters.– A set of defined response parameters.
• All have GetCapabilities (publish – find – bind).• Use GET or POST.
Web Map Service• GetMap method lets you ask for a map, specifying:
– Layers and display styles– Bounding box– Image format
• Returns a map• GetFeatureInfo lets you ask for basic
attributes.• Show GetCapabilities.
Try some example WMSs at:
• http://www.bgs.ac.uk/data/services/1gewms.html
• GetCapabilities shows you the layers
• GetMap shows you the map
• GetFeatureInfo shows some basic data.
Web Feature Service• GetFeature method lets you query features
specifying:– Feature types– Filter (attribute and spatial)– Other parameters (records to return etc).
• Returns GML data (more later).• Also transaction methods available.• Show GetCapabilities.