Session 1: Introduction to Geospatial Standards

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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

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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.
• Many OGC standards become ISO standards.

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67092008 - Standard representation of latitude, longitude and altitude for geographic point locations6709/Cor 1 191292009 - Imagery, gridded and coverage data framework
191012002 - Reference model (under revision) 19130 - Sensor and data models for imagery and gridded data
19101-22008 - Reference model - Part 2 Imagery 191312007 - Data product specifications
191032005 - Conceptual schema language (under revision) 191322007 - Location based services - Reference model
191042008 - Terminology 191332005 - Location based services - Tracking and navigation
191052000 - Conformance and testing 191342007 - Multimodal location based services for routing and navigation
191062004 - Profiles 191352005 - Procedures for registration of geographical information items
191072003 - Spatial schema 191362007 - Geography Markup Language
191082002 - Temporal schema19108/Cor 1 191372007 - Core profile of the spatial schema
191092005 - Rules for application schema 191382006 - Data quality measures (under revision as PT 19157)
191102005 - Methodology for feature cataloguing19110 Amd 1 under development 191392007 - Metadata - XML schema implementation
191112007 - Spatial referencing by coordinates 191412008 - Schema for moving features
19111-22009 - Spatial referencing by coordinates - Part 2 Extension for parametric value 19142 - Web Feature Service
191122003 - Spatial referencing by geographic identifiers 19143 - Filter encoding
191132002 - Quality principles (under revision as PT 19157) 19144-12009 - Classification Systems Part 1 Classification system structure
191142003 - Quality evaluation procedures (under revision as PT 19157) 19114/Cor. 1 19144-2 - Classification Systems Part 2 Land Cover Classification System LCCS
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191152003 - Metadata (under revision) 19115/Cor. 1 19145 - Registry of representations of geographic point location
19115-22009 - Metadata - Part 2 Extensions for imagery and gridded data 19146 - Cross-domain vocabulary
191162004 - Positioning services 19147 - Transfer nodes
191172005 - Portrayal (under revision) 19148 - Linear referencing
191182005 - Encoding (under revision) 19149 - Rights expression language for geographic information - GeoREL
191192005 - Services 19119/Amd. 1 19150 - Ontology
191202001 - Functional standards 19151 - Logical location identification scheme
191212000 - Imagery and gridded data 19152 - Land Administration Domain Model (LADM)
191222004 - Qualifications and Certification of personnel 19153 - Geospatial Digital Rignts Management Reference Model (GeoDRM RM)
191232005 - Schema for coverage geometry and functions 19154 - Standardization Requirements for Ubiquitous Public Access
19124 - Imagery and gridded data components 19155 - Place Identifier (PI) Architecture
1912512004 - Simple feature access - Part 1 Common architecture (under revision) 19156 - Observations and measurements
19125-22004 - Simple feature access - Part 2 SQL option (under revision) 19157 - Data quality
191262009 - Profile - FACC Data Dictionary 19158 - Quality assurance of data supply
19122005 - Geodetic codes and parameters 19160 - Addressing
191282005 - Web Map server interface  
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Relevant Standards Bodies W3C

• 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.

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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.

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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)

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The OGC Standards Framework

• Abstract Specifications.
• OpenGIS Standards.
• OpenGIS Reference Model.
• Best Practices Documents.
• Discussion Papers.
• White Papers.
• OGC Interoperability Experiments.

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OGC Abstract Specifications

• Platform independent abstract model.
• Reference model for the development of OGC
  standards.
• Many become ISO/TC 211 Standards.

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OGC Standards Process
Specification
Acceptance by eVote
Best Practices Document
Acceptance by full plenary at TC Meeting or
eVote (gt2 implementations)
Discussion Paper
Acceptance by Working Group Vote at TC Meeting
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(No Transcript)
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Topic 0 Overview Introduction and Roadmap. Topic 10 Feature Collections Feature Instances, Feature Schema, Project Schema
Topic 1 Feature Geometry ISO 19107. Topic 11 Metadata ISO 19115 (replaces topics 9 and 11)
Topic 2 Spatial Referencing by Coordinates Modelling requirements for coordinate referencing. Topic 12 The OpenGIS Service Architecture ISO 19119
Topic 3 Locational Geometry Structures Abstract models for GIS technology. Topic 13 Catalog Services
Topic 4 Stored Functions and Interpolation Abstract models for technology, especially coverages. Topic 14 Semantics and Information Communities
Topic 5 Features Describes geographic features. Topic 15 Image Exploitation Services
Topic 6 Schema for coverage geometry and functions Topic 16 Image Coordinate Transformation
Topic 7 Earth Imagery ISO 19101-2, ISO 19191-2 Topic 17 Location Based Mobile Services
Topic 8 Relationships between Features Topic 18 Geospatial Digital Rights Management Reference Model (GeoDRM)
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OpenGIS Standards

• A document, established by consensus, describing
  rules and guidelines for interfaces and
  encodings.
• Aimed at achieving interoperability.
• Implementation, not abstract.
• More technical, allow actual creation of the
  interfaces

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OpenGIS Implementation Specification (Interface
Standards) http//www.opengeospatial.org/standard
s/is
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Catalogue Services Specification Access to catalogue information. Multiple profiles, extension packages, discussion papers and best practice documents. Simple Features Common architecture and interfaces for access to geographic data with OLE/COM, CORBA and SQL.
Coordinate Transformation Service Standard way to specify and access and coordinate transformation services. Web Coverage Service Retrieval of geospatial data as coverages (space varying phenomena).
Filter Encoding XML encoding for filter expressions Web Coverage Processing Service Defines a language for retrieval and processing of multi-dimensional geospatial coverages representing sensor, image, or statistics data.
Geographic Objects A set of abstractions for describing, rendering, and manipulating geographic objects Web Feature Service Retrieval of geographic object-based features.
Grid Coverage Service (Retired) Raster analysis and processing. Web MapService Generation and retrieval of geo-registered map images.
Open Location Services (OpenLS) Interfaces for Location Based Applications. Web Processing Service Rules for inputs and outputs from geospatial processing services.
Sensor Observation Service API for deploying sensors and retrieving sensor data. Web Service Common Parameters and structures that are common to all OGC web service standards.
Sensor Planning Service Interface for sensor querying.
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OpenGIS Encoding Standards
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CityGML Virtual 3D city and landscape models. Observations and Measurements Abstract model and XML Schema for Observations.
Geography Markup Language XML grammar for geographic features. Sensor Model Language Models and XML encoding for sensors and sensor systems.
Geospatial eXtensible Access Control Markup Language (GeoXACML) Styled Layer Descriptor Symobolization and colouring of geographic features in WMS.
GML in JPEG 2000 Using GML with JPEG for geographic imagery. Symbology Encoding
KML Transducer Markup Language Exchange of data with sensors.
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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.

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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.

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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.

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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.

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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.

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Try some example WFSs at

• http//nsidc.org/data/atlas/ogc_services.htmlWFS
• GetCapabilities shows you the layers
• GetFeature returns features in GML
• DescribeFeatureType describes the feature type
  (schema).

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Web Coverage Service

• GetCoverage method lets you ask for raster source
  data, specifying
• Coverage name
• Bounding box
• Image format
• Returns a raster image.
• DescribeCoverage gives you basic metadata about
  the coverage.

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Filter Encoding

• An XML encoding for the OGC common catalogue
  query language (abstract spec).
• Defines
• Spatial operators (e.g. disjoint, touches,
  contains)
• Comparison operators (e.g. equalTo, like)
• Logical operators (and, or, not).
• Used in many other OGC specifications (WFS, CSW).

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OGC Standards Strengths and Weaknesses

• Strengths
• Consensus, agreed view.
• Used widely.
• Not many alternatives.
• Weaknesses
• Sometimes not very sophisticated.
• Slow to develop.
• Can be driven by an influential group or
  individual.

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Discussion

• Current use of OGC standards?
• Other standards?
• Potential for use?

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Summary

• There are many standards.
• The interactions and dependencies can be
  complicated, but most of the standards themselves
  are fairly simple.
• Interoperability is very difficult without them!