Research in GIS/GIScience

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Research in GIS/GIScience _at_UCD Computer
Science
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GISystems and GIScience Research Issues

• Multiresolution models
• Automated map generalisation
• Web-based and Mobile GIS
• Interoperable GIS

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Multiresolution Multiple Representations for Map
Data
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Multiresolution Multiple Representations for Map
Data
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Multiresolution Multiple Representations for Map
Data
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Multiresolution Multiple Representations for Map
Data
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Map Generalization
Extraction of a less detailed version of a map
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Generalization Operations

• Selection
• Aggregation
• Collapse
• Symbolization
• Simplification
• Exaggeration
• Displacement

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Geometric Problems in Map Generalization

• Simplification of lines empirical solutions and
  partial theoretical solutions Douglas and
  Peucker 1973
• Preservation of consistency (no illegal overlap)
  need for a posteriori checks
• Automated map generalization open problem

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Multiple Representations for Terrain Data
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Multiple Representations for Terrain Data

• Related problems
• simplification/refinement of the domain
  subdivision
• efficient data structures
• efficient algorithms for hierarchical query and
  reasoning

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A Multilevel TIN
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Multiple Representations for Terrains

• Efficient data structures including vertical
  links efficient hierarchical reasoning
• Algorithms for hierarchical spatial queries
• Algorithm for hierarchical overlay of plane
  subdivisions
• Visibility computation on hierarchical TINs

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Hierarchical Point Location
t0
t1
t2
t3
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Web-Based GIS
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Mobile GIS
Issues GIS and GPS integration
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Efficient Transmission

• Remote access through slow communication links
  need for coarser versions of the dataset to
  perform preliminary analysis (progressive
  transmission)
• Available
• - interleaving/compression techniques for
  raster data
• - compression mechanisms for terrain data
• No implementation for map data

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Progressive Transmission
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Progressive Vector Transmission A Solution
Based on a client-server architecture
pre-compute a sequence of consistent
representations at lower levels of detail on the
server site and transmit them in order of
increasing detail
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Multiresolution for Progressive Transmission
Client
Server
OK!
Vector Maps Library
Map 1
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Map n
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Interoperability

• OpenGIS consortium OGC
• (www.opengis.org)
• At the representation level standard model
  specifications
• Format GML
• Processes
• Web servers
• Mobile applications

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Geography Markup Language (GML)

• XML-based language for exchanging spatial data
• Geographic data content represented in text form
• XSLT (Extensible Stylesheet Language
  Transformations) used to transform GML data into
  a suitable graphics format (e.g., SVG)

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Scalable Vector Graphics (SVG)

• Text-based vector data format
• Easily compressed
• SVG elements directly correspond to GML features
• SVG viewer PocketSVG viewer from CSIRO

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PROJECTS

• 1. Knowledge Management for
• Geo-Spatial Imagery
• CoMPASS Combining Mobile Personalised
  Applications with Spatial Services
• MEMS Mobile Environmental Management System

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Knowledge Management for Geo-Spatial Imagery
(MaGIK)
Sponsor 2001 Enterprise Ireland Research
Innovation Fund Participants M. Bertolotto,
D. Wilson, Eoin McLoughlin, Dympna
OSullivan
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Sketch-based Geo-Spatial Image Retrieval
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Knowledge Management
Knowledge Base
Image Database
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MaGIK on-going work
MaGIK Mobile transferring MaGIK to the mobile
platform GUI development current 4th year
project
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CoMPASS Combining Mobile Personalised
Applications with Spatial Services
Sponsor 2002 Enterprise Ireland Advanced
Technologies Research Programme Participants M.
Bertolotto, D. Wilson, Julie Doyle,
Dan Lynch, Joe Weakliam, Helen Min
Zhou Eoin McAoidh
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Location-Based Services
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Spatial Services

• Display maps
• Annotate maps
• Personalise maps

Associated text message
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Technologies Employed

• Oracle Spatial database and application server
• Java application programs
• JDBC
• GML and SVG
• Pocket PC with GPS receiver
• Web client

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Web-based GUI OpenMap

• Opensource GIS sw package
• Java-based
• Web-based GUI to Oracle Spatial DB

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OpenMap GUI
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OpenMap GUI
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Mobile GUI

• GML
• SVG
• iPaq Pocket PC

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Interface for Pocket PC
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MEMS Mobile Environmental Management System
Sponsor 2004 Enterprise Ireland Innovation
Partnership Programme Participants M.
Bertolotto, A. Rizzini In collaboration
with Digital Media Centre, DIT E-Spatial
Solutions Ltd.
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Mobile Environmental Management System
Deliver text-based field data sheets used by
scientist of the Canadian Department of Fisheries
and Ocean Plus additional multimedia
information to a spatially-enabled DB with
mobile access
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