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Volunteered Geographic Information (VGI) and communicating geospatial data Quality of 3D objects in Virtual globes. Krista Jones 1 , Rodolphe Devillers 1,2 , Yvan Bédard 2 and David Coleman 3 1 – Dep . of Geography, Memorial University of Newfoundland 2 – Dep . of Geomatics, Université Laval

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slide1

Volunteered Geographic Information (VGI) and communicating geospatial data Quality of 3D objects in Virtual globes

Krista Jones1, Rodolphe Devillers1,2, Yvan Bédard2 and David Coleman3

1 – Dep. of Geography, Memorial University of Newfoundland

2 – Dep. of Geomatics, Université Laval

3 – Dep. of Geomatics Engineering, University of New Brunswick

outline
Outline
  • Volunteered Geographic Information (Rodolphe)
    • Whatisit?
    • Whyisituseful to data producers?
    • Workdone in our GEOIDE project (David Coleman’s team)
  • Data quality visualization of 3D VGI (Krista)
    • Context
    • Research Problem
    • Visualization Method & Approach
    • Perceived Quality
    • Prototypes & Testing
    • Future Work
    • Conclusions
outline1
Outline
  • Volunteered Geographic Information (Rodolphe)
    • Whatisit?
    • Whyisituseful to data producers?
    • Workdone in our GEOIDE project (David Coleman’s team)
  • Data quality visualisation of 3D VGI (Krista)
    • Context
    • Research Problem
    • Visualization Method & Approach
    • Perceived Quality
    • Prototypes & Testing
    • Future Work
    • Conclusions
what is vgi
Whatis VGI?
  • VolunteeredGeographic Information (VGI)
    • Response of the geospatialcommunity to the “Web 2.0”
    • Specific type of “User-generated content”
    • Can be used for “crowdsourcing”
  • Citizens (the lay people) produce and sharegeographic information
    • E.g. OpenStreetMap, Wikimapia
what is vgi1
Whatis VGI?

Example: OpenStreetMap

why vgi
Why VGI?
  • Many data producers are exploring the possibility to use crowdsourcing to producegeographic information
  • “It doesn’t make sense, they are not professionals”
    • Well, two recent studies (Haklay 2010 and Girres and Touya 2010) show that OpenStreetMap is generally more accurate than maps from the OS or IGN-France…
slide7
VGI
  • Number of questions/issues remain:
    • Completeness (heterogeneous quality)
    • How can one assess
      • the reliability of the contributor
      • the quality of the data produced
    • Questions of liability (who is liable?)
work done in the geoide project coleman et al @ unb
Work done in the GEOIDE project(Coleman et al. @ UNB)

To investigate and demonstrate how

…..volunteered contributions of geospatial data from both individual citizens and professional mapping organizations ….

…may be authenticated, processed and employed to populate new public, government and commercial map databases.

essential questions
Essential Questions
  • Why would individuals want to contribute anyway (and what keeps them contributing)?
  • What is the authoritative mapping organization\'s rationale for considering VGI? What mission, objective or problem is being addressed?
  • To what extent, if at all, should VGI be adopted?
  • How may credible VGI contributors be qualified?
  • How may incorrect, misleading or damaging contributions be identified and excluded?
  • How much control over content and quality are such organizations prepared to relinquish? Who makes the final decisions regarding the reliability of a given update?
who are the volunteers in vgi
Who are the "Volunteers” in VGI
  • Can we characterize them?
  • Can we characterize their contributions?

Coleman, D.J., Georgiadou, Y. and Labonte, J. [2009]. "Volunteered Geographic Information: The Nature and Motivation of Produsers." International Journal of Spatial Data Infrastructures Research Vol. 4. http://ijsdir.jrc.ec.europa.eu/index.php/ijsdir/article/view/140/198.

3 vgi case studies to date
3 VGI Case Studies to Date
  • USGS National Map Corps Initiative
  • Notification and Editing Service, Dept. Of Sustainability and Environment, State of Victoria, Australia
  • TomTom\'sMapShare™ Service

Coleman, D.J., Sabone, B. and N. Nkhwanana [2010]. "Volunteering Geographic Information to Authoritative Databases: Linking Contributor Motivations to Program Effectiveness". Geomatica Vol. 64, No. 1 pp. 383-396. Special Issue on Volunteered Geographic Information. March.

follow on research @unb
Follow-on Research @UNB
  • Positional Accuracy Assessment of VGI Tools
  • Assessing Credibility of Contributors and Reliability of their Contributions

Coleman, D.J. [2010]. " The Potential and Early Limitations of Volunteered Geographic Information". Accepted for publication in Geomatica , Vol.64, No.2. Special Issue on 50th Anniversary of the Department of Geodesy and Geomatics Engineering at the University of New Brunswick. June.

outline2
Outline
  • Volunteered Geographic Information (Rodolphe)
    • Whatisit?
    • Whyisituseful to data producers?
    • Workdone in our GEOIDE project (David Coleman’s team)
  • Data quality visualization of 3D VGI (Krista)
    • Context
    • Research Problem
    • Visualization Method & Approach
    • Perceived Quality
    • Prototypes & Testing
    • Future Work
    • Conclusions
context virtual globes
Context - Virtual Globes
  • Very recent technology/concept
    • Al Gore 1998
    • NASA’s World Wind (2003) & Google Earth (2005)
  • Virtual Globes: Important tool for the democratization of geospatial information
  • Integrate 3D data (e.g. city models)
  • Users can create, share and view 3D models

Google Sketchup

World Wind

problem heterogeneous quality of 3d models
Problem - Heterogeneous Quality of 3D Models
  • The quality of user-generated 3D objects can be very heterogeneous
    • The level of realism of a model does not always indicate its accuracy
    • Novice and expert users can rarely assess the quality of 3D objects
    • There are then risks related to decision making based upon these models

Model created by: User 1

Model created by: User 2

problem current visualization methods
Problem – Current Visualization Methods
  • The visualization of uncertainty/data quality has been the subject of numerous research projects
  • Many methods have been proposed, but none have been used in widespread practice
    • Complexity
    • Technical feasibility

Glyphs

Transparency

Wireframe

visualization method approach
Visualization Method & Approach
  • Symbiotic Approach
    • Trade-off to make sure that everything works together as a whole
      • “holistic approach”
    • Term which refers to the balance between the simplicity and detail of the method
    • Richness of visualization vs. ease of understanding

VS

    • Technical feasibility

simplicity

detail

visualization method approach1
Visualization Method & Approach
  • Amazon.com - visual variable value is used to convey the rating of the product
visualization method approach2
Visualization Method & Approach
  • 5 Star System
    • Approach inspired by other systems (e.g. Amazon, EBay, iTunes)
    • Users can:
      • Assess the quality on a 1 to 5 rating system
      • Add more detailed comments
    • Assessing appropriate ways to geospatially visualize stars
perceived quality
Perceived Quality
  • New concept of "perceived quality" (vs. measured) for geospatial information
  • Perception which a user has about the quality of data for their own needs
    • By examining a model the user then gauges what the quality of the dataset is for their personal use based on other users commentary and feedback
prototypes testing
Prototypes & Testing
  • Tests of representations of stars
    • Using various visual variables (size, color, etc.)
    • Using different geometries for stars (2D vs 3D)
prototypes testing1
Prototypes & Testing
  • Quality slider
  • User comments
prototypes testing2
Prototypes & Testing
  • In progress
    • Representation of stars
    • Google Earth
    • Two cities
      • San Francisco and Prague
      • Different urban characteristics for testing of visualization methods
conclusions
Conclusions
  • Developed a symbiotic approach which combines a detailed assessment (feedback) with a simplified display (stars)
  • New approach based on users’ perception of quality
  • Novel way to collect and display quality of 3D objects in virtual globes
  • Allows non-expert users to understand the quality of the data they are using for decision-making
  • Method usable for any other type of 3D object (not just buildings)
acknowledgments
Acknowledgments
  • GEOIDE
  • Memorial University of Newfoundland
  • Natural Sciences and Engineering Research Council of Canada (NSERC)
  • NSERC Industrial Research Chair in Geospatial Databases for Decision Support
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