A presentation at the OGC Interoperability Day

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CGDI Architecture

• A presentation at the OGC Interoperability Day
• Ottawa
• April 23, 2004

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Agenda

• Overview of CGDI
• Architecture Status
• Specifications
• Resources

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CGDI Vision

• A Canadian geospatial information
  infrastructure that is accessible to all
  communities, pervasive throughout our country,
  ubiquitous for its users, and self-sustaining, to
  support the protection and betterment of Canada's
  health, social, cultural, economic and natural
  resource heritage and future
• Putting Canadas Geographic Information on the
  Internet

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CGDI characteristics

• Many pieces working independent of make, model
• Open interface
• Can communicate with other things
• Transparent / Invisible
• Cooperative
• Distributed

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CGDI Enabled Applications
CGDI will enable geospatial applications with
online data and services
e.g. Sustainable Development Transportation
Planning Climate Change Monitoring Disaster
Response Site Assessment Infrastructure
Portal ...
e.g. Features Coverages Projects, Studies,
Activities Events, Situations ...
e.g. Discovery Gazetteer Visualization
Location-based ...
Consumers will be able to access many kinds of
geospatial capabilities
.
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CGDI View From 50000 ft.
Standards (OGC,ISO)
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Conceptual Model - CGDI
CGDI enabling infrastructure of geospatial data
and services
Provincial Portals/Infrastructures
Community Gateways/Portals
Ontario
Northern Information Network
Nova Scotia
Vendor Infrastructure
National Land Water Info Sys
Access
ESRI Geography Network
Federal Infrastructures
Technology Innovation
Cdn Info System for the Env.
Standards
Policy
Sustainable Communities
Frameworks
Global Infrastructures
Global Spatial Data Infrastructure
Service Programs
Atlas of Canada
Intl-Fed-Prov Partnerships
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What does the CGDI vision imply?

• More than just a collection of web service
  specificationsmore than just GIS on the web.
• Authoritative data (Framework data)
• Coordinating systems
• Standard access mechanisms (specifications)
• Security
• Reliability
• Reusable components
• Education

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CGDI Architecture Working Group(CAWG)

• Designs CGDI architecture
• Identifies needs and recommends solutions
• Identifies standards where available
• Facilitates development of new standards where
  necessary
• Makes recommendations to the CGDI Technology
  Advisory Panel (TAP)
• Who
• Combination of Canadian government and industry
  technology leaders
• Membership open to all

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• CGDI Architecture Status
• Framework Data
• Coordinating systems
• Standard access mechanisms
• Security
• Reliability
• Reusable components
• Education

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1. Framework Data

• Basic datasets have been identified, at two
  levels of resolution
• but
• Datasets are not all complete and available

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2. Coordinating Systems (1 of 2)

• Basic services identified, and some have been
  implemented
• Discovery Portal, Gazetteer
• but
• Basic services are having trouble keeping up with
  changes in specifications
• Some essential services are missing or inadequate
• Registries for services, SLDs, etc
• Some implementation issues remain
• Redundancy

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Master systems

• provide authoritative information
• Architecture Specifications
• Specification descriptions
• Profiles and schemas
• (Manually maintained website)
• Framework Data Registry
• (Manually maintained website)

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Primary systems

• provide core services
• Geodata Discovery
• Service Registy
• Component Registry
• Event Registry
• Other Registries (FE, SLD, schema)
• Gazetteer

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3. Access Mechanisms (1 of 2)

• Standards based interfaces to facilitate access

Registries for services and data
Provider
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Access Mechanisms (2 of 2)

• Basic interfaces identified
• WMS, WFS, GDAS, etc.
• but
• Specifications have not been implemented by all
  agencies
• Some issues remain, primarily around registries

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4. Security

• A recommendation paper has been drafted, and a
  few organizations have taken steps to implement
  some security measures
• but
• Most organizations have not
• Knowledge and experience is a limiting factor.

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5. Reliability and redundancy

• A recommendation paper has been drafted, and a
  limited number of redundant services are
  available,
• but
• Most organizations have not had to deal with
  reliability issues yet.
• Knowledge and experience is a limiting factor.

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6. Reusable Components

• Reusable components have been developed
• but
• Components are not all based on CGDI
  specifications
• Grass roots have not become engaged in the
  development or use of these components

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7. Education

• Training materials have been developed
• but
• Training materials have not been tested
• Training materials are already partly obsolete
• Training has not been picked up by educational
  institutions

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• CGDI Specifications
• Endorsed
• Interim
• Proposed
• Unusual (non-OGC)

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Endorsed Specifications

• Web Map Service
• Web Feature Service
• Geodata Discovery Service
• Geodata Resource Registry
• Z39.50 and FGDC Geo profile
• ISO 19115
• Geographic Markup Language (GML)
• GML 2 and 3
• Styled Layer Descriptor (SLD)
• Filter Encoding
• Web Map Context

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Interim Specifications (1 of 2)

• OGC Web Coverage Service
• OGC direction supported
• specification not yet ready for endorsement
• CGDI Gazetteer Service
• OGC direction supported
• CGNDB implementation is being used as an interim
  standard

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Interim Specifications (2 of 2)

• OGC Service Registry Service
• OGC direction supported
• CGDI interim / add-on approach developed
• CGDI Geolinked Data Access Service
• developing into a defacto CGDI standard
• submitted to OGC as a discussion paper
• CGDI Geolinking Service
• submitted to OGC as a discussion paper

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Proposed specifications

• Overlay service
• Data reallocation service
• Modelling (geoprocessing) service
• Event notification service

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Unusual spec 1Service Registry Service (1 of 2)

• A standard way of documenting, publishing and
  finding services, based on
• The service provider publishes a service
  description on their website
• The service provider submits the URL to the
  Service Registry Service, to initiate ongoing
  harvesting.
• A simple google-like interface for users to query
  the Service Registry.

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Unusual spec 1 Service Registry Service (2 of 2)

• Service descriptions include
• An XMLRDF description (mandatory)
• A plain text description in HTML (optional)
• A Web Services Description Language (WSDL)
  description (optional)

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Unusual spec 2 Geolinked Data Access Service

• A standard way to access attribute data that
  applies to spatial frameworks
• Simple XML stream
• Carries metadata about the data and the framework
  dataset.

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Unusual spec 3 Geolinking Service

• A standard way to do a spatial join on attribute
  data to a spatial framework
• Supports WMS (real time mapping)
• Supports modelling.

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Resources

• CGDI Developers Corner
• Development network meetings and workshops
  (presentations)
• Key Documents
• Technical Specifications
• Training Materials
• Working Examples
• Todays technology demonstrations.

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CGDI Architecture

• http//geoconnections.org