WMS Map Integration -Improved

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WMS Map Integration -Improved

• Ghulam Memon
• Ashraf Memon

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Contents

• WMS Review
• Problems with previous viewer
• OGC WMS Viewer
• WMS Integration Architecture Improved
• WMS Registration Improved
• Future Goals

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WMS Review

• An OGC standard, which can retrieve map images
  from any complying server.
• 3 versions so far i.e. 1.0.0, 1.1.0 and 1.1.1
• Current implementation uses HTTP to send and
  receive messages.
• Supported operations (required)
• GetCapabilities Used to retrieve metadata for a
  WMS Service, exposed by publisher.
• GetMap Used to retrieve map image for specified
  layers within a specific envelope in a WMS
  Service.

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Registration Architecture

1. WMS URL(s)
2. ADN Metadata
3. RegistrationOntology Name (Optional)

GetCapabilities
WMS Server
WMS Registration Porlet
GetCapabilities
Compile
Ontologies and Concepts
WMS Server

1. WMS URL
2. ADN metadata
3. Ontology Name
4. Service Envelope
5. WMS Version Supported
6. Layer Names
7. Layer Styles
8. Layer Projections
9. Layer Envelope

SRB
REGISTER ADN Metadata
GEON Metadata Catalogue
REGISTER
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Map Integration Architecture
GEON Metadata Catalogue

1. Selected GEON Ids

1. WMS URL
2. Service Envelope
3. WMS Version Supported
4. Layer Names
5. Layer Styles
6. Layer Projections

WMS Registration Porlet

1. Selected GEON Ids

WMS Integration Service
GetImage
WMS Server
GetImage
WMS Server
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Integrating Multiple WMS Services - Issues

• Projection Negotiation
• Layer Sequencing
• Quality of Service
• Granularity of Integration
• Lack of a better viewer

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Problems with previous viewer

• Lack of compliance with WMS standards
• Lack of traditional ArcIMS Viewer like features
• Lack of a flexible programmer interface
• Not scalable
• Doesnt incorporate the notion of WMS layers
• No support for legend
• Doesnt support identify operation, even if the
  layer does

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OGC WMS Viewer

• Eliminates all previous problems
• Supports Web Map Context Specification
• An XML based OGC standard developed as a
  companion specification to WMS 1.1.1
• Serves the core purpose of describing an
  integrated view of different WMS layers (not
  services) requested from different servers
• Perfect for GEONs needs of personlaization
  (myGEON)
• Standardization and use of XML makes it portable
  across different viewers
• In GEONs particular case, WMC helped to derive
  the database schema

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Map Integration Architecture - Improved
GEON Metadata Catalogue
WMS Registration Porlet
Selected GEON Ids
WMS Info
Selected GEON Ids
WMC file
WMS Integration Service
GetImage
OGC WMS Viewer
GetImage
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WMS Registration - Improved

• Download and parse the capability document for
  WMS Service.
• The improved interface allows the user to fill
  metadata only if the URL is valid
• Incorporates two levels of errors i.e. service
  and layer levels
• Users can select the layers that need to be
  registered
• Users can register multiple layer/datasets
  without entering metadata for every layer

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Future Goals

• Heterogeneous Resource Integration
• Shapefiles
• GeoTiffs
• ArcIMS Services
• NetCDF files
• Automated Discovery and registration of
  distributed data sources