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Openstreetmap, GPS traces and positioning


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Presentation in Mobile Tartu 2010 seminar

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Openstreetmap, GPS traces and positioning

  1. 1. OpenStreetMap and positioning<br />JaakLainesteOpenStreetMap Estonia<br /><br />
  2. 2. OpenStreetMap<br />Wikipedia of maps<br />Global database<br />Focused to current street maps<br />No elevation, history etc<br />Community<br />300.000+ registered users<br />Very strong in Germany<br />Free and open to use<br />CC-BY-SA license<br />
  3. 3. How OSM is created<br />Field mapping<br />GPS traces<br />Walking Papers – paper notes<br />On-screen mapping<br />Yahoo! Imagery<br />Regional sources: e.g. Estonian National Land Board<br />Imports<br />USA: TIGER data<br />Europe: Corine Land Cover etc<br />
  4. 4.
  5. 5. Mapping parties<br />
  6. 6.
  7. 7. Data in OSM Databases<br />Map data<br />Nodes, ways, relations<br />Tagged openly<br />History: who, when, changesets<br />GPS traces<br />Base for map<br />
  8. 8. GPS Trace data<br />HTTP REST-based API<br />Based on BBOX<br />Tracks and trackpoints (lat/long)<br />No timestamp, user ID<br />GPX format (simple XML) <br />Someone has been in point X<br />Track details from database<br />Timestamp, user ID<br />
  9. 9. Map data<br />Ways and nodes:<br />User ID<br />Editing time<br />Information about locations:<br />Probably editor has been in the point around editing time (+ maybe few weeks)<br />Density of different editors<br />Quite ambiguous<br />
  10. 10. London – different editors<br />ITOWorld extract<br />
  11. 11. Using OSM data<br />GPS track<br />High precision – time and location<br />Less users<br />Map locations<br />Low precision<br />More users<br />Movement distribution<br />Places what and when users have visited<br />
  12. 12. OSM advantages<br />Coverage is:<br />Global<br />Quick, get the data now<br />Free<br />Real usability?<br />Real coverage is variable<br />
  13. 13. Coverage statistics<br /><br />Registered users: ~300,000, <5% active<br />About 6,000 editors/week<br />Tracks<br />Points: ~200,000,000,000 <br />Traces: 800,000 traces<br />Map nodes: ~ 750,000,000<br />
  14. 14. Key issues<br />User is in „mapping mode“. May be special trip<br />Most mappers do not upload/share GPS traces<br />User can trace aerials, without being there<br />Regional differences<br />Very good in e.g. Germany, UK<br />Limited in e.g. US (TIGER imports)<br />
  15. 15. Other uses of OSM<br />Use OpenStreetMap as a base map<br />Positioning accuracy improvement <br />GPS trace shows where people are more probably<br />Share your GPS traces in OSM<br />Contribute to OSM<br />fix map of your neighbourhoods!<br />
  16. 16. Study: distribution of GPS traces<br />Two random cities picked<br />Tartu, Estonia – well-known town<br />Weimar, Germany – unknown town<br />GPS traces downloaded for town area<br />Tartu – 9x9 km, 160.000 points, 42 tracks<br />Weimar – 7x7 km, 100.000 points, 33 tracks<br />Spatial distribution of traces<br />Visualized in 50 or 100-m grid<br />
  17. 17. Tartu map in OSM<br />
  18. 18. Tartu GPS traces<br />
  19. 19. Tartu, 100m grid of GPS points<br />
  20. 20. Weimar map<br />
  21. 21. Weimar, GPS trackpoints<br />
  22. 22. Weimar, 50m grid<br />
  23. 23. Map of central London<br />
  24. 24. GPS traces<br />
  25. 25. GPS points on map<br />
  26. 26. London grid<br />Points: 440 000, tracks: 220<br />
  27. 27. Thank you!<br />Jaak Laineste<br /><br /><br /> <br />Credits: Microsoft support for fixing my PowerPoint<br />