Higher Education Atlas Using Open Source Tools
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Higher Education Atlas Using Open Source Tools
- 1. Higher Education Profiling using Open Source GISA Primer on OpenStreetMap Data, Mapnik & OpenLayers Oliver O’Brien & Alex Singleton Department of Geography University College London
- 2. Contents The Problem Requirements The Solution OpenStreetMap Data Mapnik OpenLayers Data Sources Putting it all Together The Completed Atlas
- 3. The Problem: Presenting the Data A large amount of education-related spatial information available from various governmental bodies but not in a readily accessible graphical form (i.e. maps) for non-technical users. Dept. for Schools, Children and Families Communities and Local Government Higher Education Funding Council for England Higher Education Statistics Agency Office for National Statistics “Widening participation” initiatives require effective ways to view such data, to make decisions on target schools and areas.
- 4. Requirements I. Straightforward Standalone GISes Hard to use (Haklay, 2009a) Often expensive Require delivery of data to the client
- 5. Requirements I. Straightforward Web GISes Slow Unattractive Difficult and/or expensive to build May require delivery of vector data to the client
- 6. Requirements I. Straightforward “Slippy Maps” Simple to use Very popular Simple to build Powerful API (e.g. Google Maps API)
- 7. Requirements II. Accessible Software installation Requires time and skill Constrained by platform Plug-ins Generally require a fast computer Still some platform issues A solution without installation or plug-ins is most accessible HTML, CSS, AJAX PNG images
- 8. Requirements III. Self Contained No dependencies on third parties with constraints Ordnance Survey “tile limits” The “derived data” problem, Google and Ordnance Survey Can’t put Ordnance Survey derived data on a Google Maps “mashup” Government departments often provide data that has been geolocated from Ordnance Survey mapping (e.g. using National Grid References) Ordnance Survey is being very active at protecting use of its data at the moment
- 9. Requirements III. Self Contained Full control over what’s on the map Google’s colour scheme and branding can be distracting
- 10. The Solution: An Education Atlas Static tiles of choropleth maps Minimal computer requirements Scalable Mapnik Makes “beautiful” raster maps OpenStreetMap data Easily available data source to create background maps Full control over what is included OpenLayers Provides the “slippy map” interface familiar to users Self-contained
- 11. Using OpenStreetMap Data For a background map to provide context Will include roads, town names, coastlines We don’t want all the data – just what we need Ways to obtain the data Directly from osm.org as XML, requires converting Shapefiles produced by CloudMade or Geofabrik Data quality and completeness Improving rapidly (Haklay, 2009b) Now pretty good for England (Reed, 2009) Can always obtain a very up-to-date dataset www.openstreetmap.org
- 12. Using Mapnik “Mapnik is a Free Toolkit for developing mapping applications. Above all Mapnik is about making beautiful maps.” – mapnik.org Data Sources Shapefiles PostGIS databases Direct from OpenStreetMap Tiles Can be configured to systemically create square tiles at different zoom levels for the whole country www.mapnik.org
- 13. Using Mapnik Stylesheets for the cartography e.g. minor rivers and canals <Rule> <Filter>[waterway]='river' or [waterway]='canal'</Filter> <MaxScaleDenominator>80000 </MaxScaleDenominator> <LineSymbolizer> <CssParameter name="stroke">#88c <CssParameter name="stroke-width">3 <CssParameter name="stroke-linejoin”>round <CssParameter name="stroke-linecap">round </LineSymbolizer> <TextSymbolizername="name" face_name="DejaVu Sans Book" size="10" fill="#666" halo_radius="1" placement="line" min_distance="200"/> </Rule>
- 14. Using OpenLayers A way to display maps on a website Just a simple web browser is needed Accepts “layers” from many sources Google Maps Microsoft Bing, Virtual Earth, Yahoo ArcGIS 9.3 Mapping Services Ordnance Survey OpenSpace More powerful (but more complex) than the popular Google Maps API www.openlayers.org
- 15. Other Data Sources New Popular Edition Postcoding Government Data Combined with UKBORDERS boundary data, to create choropleths of each educational metric Includes the National Pupil Database with postcode, for Key Stage 4 (GCSE) and Key Stage 5 (A-Level)
- 16. Putting it all Together: Tile Generation OpenStreetMap API Stylesheet Geofabrik Shapefiles Mapnik PostGIS Database Other .gov.uk Tiles Shapefiles UKBORDERS mySQL Database DSCF.gov.uk
- 17. Putting it all Together: The Website Web Browsers OpenLayers Tiles mySQL Database The layers in OpenLayers Top: Schools (pins) Middle: Network (B&W) NPEMap Postcodes Bottom: Choropleth (colours)
- 18. The Completed AtlasIDACI in Hampstead vs. Willesden, London
- 19. The Completed AtlasA-Level French Popularity in S.E. England
- 20. Putting it all Together: The Completed AtlasA-Level Geography Popularity in England
- 21. The Completed AtlasOutput Area Classification in Manchester
- 22. The Completed AtlasIDACI in Manchester
- 23. The Completed AtlasGCSE Performance in Manchester
Notes de l'éditeur
- DCSF – attainment. CLG – IDACI. HEFCE – POLAR. HESA – school-to-university flows. ONS - for census information, from which are derived the Output Area Classifications. Widening participation is also known as Access to Higher Education.
- Using ArcGIS as an example here as it is the dominant GIS application, however there are numerous other such as MapInfo, GRASS, Quantum GIS. Some are easier to use, some harder, but almost all require skills beyond that of the average web browser.
- Slow – on-the-fly vector display, so slow on the client, or on-the-flyrasterisation, so slow on the server.Unattractive – produced by a GIS rather than a cartographical application, so generally no anti-aliasing or generalisation techniques applied.Difficult/expensive to build – May require delivery of vector data – licensing issues, as the client has a “digital copy” of the vector data, rather than a degraded raster.
- Because they are popular, users don’t need “special skills”
- Flash is popular, but not available on the iPhone.
- If data supplied includes only National Grid References and not latitude/longitude, there is a good chance that it has been derived from Ordnance Survey data. Therefore, in theory, placing that data on a Google Map “mashup” would allow Google ownership of that data, which Ordnance Survey forbids.Ordnance Survey sent a letter to all district councils in the UK recently, advising them of the derived data problem.
- Note the added “Parks” symbols roughly correspond to some (but not all) of Google’s own “Tree” symbol for public parks. It would be better if we could choose not to show Google’s own one. Also, you are stuck with Google’s colour scheme – here, the green is different to the green of the main website.
- OS OpenSpace have built their own version of OpenLayers, which can be used to display Ordnance Survey mapping imagery. However you cannot directly use the OpenSpace maps in a standalone version of OpenLayers.
- OS OpenSpace have built their own version of OpenLayers, which can be used to display Ordnance Survey mapping imagery. However you cannot directly use the OpenSpace maps in a standalone version of OpenLayers.
- The data sources are on the left. The intermediate systems are in the middle. The systems used in the final map are in the box on the right.