Isovist Analyst Extension for ESRI ArcView/ArcMap
Upcoming SlideShare
Loading in...5
×
 

Isovist Analyst Extension for ESRI ArcView/ArcMap

on

  • 1,089 views

 

Statistics

Views

Total Views
1,089
Slideshare-icon Views on SlideShare
1,087
Embed Views
2

Actions

Likes
0
Downloads
15
Comments
0

1 Embed 2

http://www.linkedin.com 2

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Isovist Analyst Extension for ESRI ArcView/ArcMap Isovist Analyst Extension for ESRI ArcView/ArcMap Document Transcript

    • Isovist AnalystArcView 3 Extension forUrban Viewshed AnalysesSanjay Rana
    • BackgroundIsovist AnalystDescription Minimum RequirementsAn isovist is a term used in urban • Lines or Polylines or Polygonsplanning for the area visible from as obstacles.a viewpoint (see figure below). • Points as viewpoints. Isovist Analyst is an ArcView 3.x Download & Informationextension for computing several • www.ucl.ac.uk/~ucessan/properties of isovists e.g. isovist • Free for personal and non-area, shape of isovists (see profit purposes.bottom right figure). • Comments/queries are welcome at s.rana@ucl.ac.uk Isovist Descriptors Isovist Mesh of viewpoints in Tate Britain Gallery, London Viewpoint © T. Joliveau Isovist Area Longest Diameter LengthPhotograph of the area taken at theviewpoint looking North-West High Low 1
    • Potential Applications of Isovist AnalystAutomated Generation of Geographical Contextin Photograph DatabasesThierry Joliveau~ and Sanjay Rana~ Université Jean Monnet- Saint Etienne, FranceProblemThe large databases of digital photographs collected by the public(e.g. flickr, panoramio) and government often lack geographicalcontext such as part of the city where the photographs weretaken, geographic objects (e.g. statues, buildings, hills etc.)visible in the photographs and so on.SolutionThe EXIF tags of geo-tagged photographs contain the exactgeographic location, azimuth, and field of view, which can beused to construct the viewshed-polygon of these photos. Now,with simple intersection tests between the landmark features andviewshed of photos, one could automatically construct thegeographical context (e.g. keywords) for these photos e.g. for thepurpose of gazetteer based querying of photograph databases e.g.Show me all the photos that have a view of the Statue in PlaceJacobins in Lyon (France). 1The Statue inPlace Jacobins 2 © T. Joliveau Sites where photos of downtown Lyon (France) are © T. Joliveau available in the Photos corresponding to Photographs the selected isovists database Isovists of photos that contain the Statue 2
    • Potential Applications of Isovist AnalystEnhancing Wayfinding Instructions withVisibility of Local LandmarksProblemMost automated wayfinding instructions for route planning andgeneral sight-seeing are based on the use of transport networkfeatures e.g. turn left at street x on to street y and so on. Wehowever also often include other cues such as visibility of locallandmarks in our referencing scheme, which is particularlysignificant when the transport network signs are not available dueto poor signage or inside buildings (e.g. museums).SolutionAn intuitive and humane set of wayfinding instructions can beproduced by carefully inserting the visibility of certain keylandmarks along the proposed route as they become visible ateach step of decision making. Walking Directions from UCL to British MuseumArea and Landmarks Conventional Improved instructions instructions UCL Turn Left onto Turn Left onto Gower Street, Gower Street [Keep going past Torrington Bookshop Senate Place intersection where Continue onto House there is a bookshop] Bloomsbury Street [You will see the Senate Museum House on your left at the Turn Left into Gower Street-Store Street Great Russell intersection] Street Continue onto Bloomsbury©Google-TeleAtlas Street. [You will see…]Further Information• Read more in Martin Raubal and Stephan Winter, 2002, Enriching Wayfinding Instructions with Local Landmarks, GIScience 2002. 3
    • Potential Applications of Isovist AnalystPlanning and Evaluating Coverage of VisualSurveillance Network InstallationsProblemThe planning and evaluation of a visual surveillance network e.g.CCTV is a complicated and delicate process. The objective ofplanning and evaluation is to ensure the maximal visual coveragewith a minimal number of visual surveillance sites. The coverageinfluences the effectiveness of the surveillance, which is relevantin the evaluation.SolutionAn add-on to the Isovist Analyst, called Art Gallery ProblemSolver can find out a minimal number of viewpoints that provide acomplete visual coverage of an arbitrary open space. This can beuseful for planning a CCTV network and evaluating the coverageof existing CCTV cameras. Mesh of Potential Sites for CCTV 65 Sites for CCTV Camera Camera Installation in Installation which will provide downtown Lyon (France) complete Visual CoverageFurther InformationRead about a real example in page 10 of the UK Home OfficeResearch Report on Methods used in assessing the impact of CCTV,Available at www.homeoffice.gov.uk/rds/pdfs05/rdsolr1705.pdf 4
    • Potential Applications of Isovist AnalystPlanning and Evaluating Coverage of VisualSurveillance Network InstallationsProblemThe planning and evaluation of a visual surveillance network e.g.CCTV is a complicated and delicate process. The objective ofplanning and evaluation is to ensure the maximal visual coveragewith a minimal number of visual surveillance sites. The coverageinfluences the effectiveness of the surveillance, which is relevantin the evaluation.SolutionAn add-on to the Isovist Analyst, called Art Gallery ProblemSolver can find out a minimal number of viewpoints that provide acomplete visual coverage of an arbitrary open space. This can beuseful for planning a CCTV network and evaluating the coverageof existing CCTV cameras. Mesh of Potential Sites for CCTV 65 Sites for CCTV Camera Camera Installation in Installation which will provide downtown Lyon (France) complete Visual CoverageFurther InformationRead about a real example in page 10 of the UK Home OfficeResearch Report on Methods used in assessing the impact of CCTV,Available at www.homeoffice.gov.uk/rds/pdfs05/rdsolr1705.pdf 4