Overview of OHM. Slides created for OpenDataCamp and re-used for SotM-FR, Brest 2015.

1. JerryJerry CloughClough
SK53 on OpenStreetMap
@SK53onOSM
SK53.osm@gmail.com
Maps Matter Blog :
www.sk53-osm.blogspot.com

2. OHM Strapline CandidatesOHM Strapline Candidates
–A map of everything that has
ever existed
–Putting a time-slider on the World
–The World's most out of date
map

3. OpenHistoricalMapOpenHistoricalMap
● Newish project, kicked-off SF
April 2013
● Based on OpenStreetMap
technology ('the stack')
● No formal ontology or rules
– Elements & Time described by
free-form tagging
– No validation
● Mainly repository of vector map
data
● Open data
(OdbL/CC-BY-SA)
● Close links with
– Wikimedia Commons (Wikimaps)
– GLAM (Galeries, Libraries, Archives &
Museums) Wiki
– Wikidata
– OpenStreetMap
– Open Knowledge Foundation
● Participants
– GIS specialists (e.g., Topomancy LLP)
– Academics (mainly CS)
– Wikimedians
– OpenStreetMappers
● Infrastructure hosted by Topomancy
URL: www.openhistoricalmap.org

4. OSM Historical Starting Point

5. OSM Nottingham : Example 1
Dead Pubs

6. OSM Nottingham : Example 2
Listed Buildings &
Old Maps
http://osm-nottingham.org.uk/?z=16&lon=-1.15010&lat=52.95162&bgl=Salmon,1,11&l=listedbuildings&lh=GradeII

7. Open Historical MapOpen Historical Map
NowNow

8. Step 1 : Georectify Old Map(s)
http://mapwarper.net

9. Step 2 : Create vector map in editor

10. Step 3 : Render the data

11. DerbyDerby
RoadRoad

12. DerbyDerby
RoadRoad

13. DerbyDerby
RoadRoad
No. Start location End location Start Date End Date
1 Priory
Roundabout
Adams' Hill 1800 9999
2 Adams Hill Lenton Lodge 1800 1825
3 Adams Hill Lenton Lodge 1825 9999
4 Lenton Lodge W of Rose and
Crown
1800 9999
5 W of Rose and
Crown
E of Rose and
Crown
1800 1936
6 W of Rose and
Crown
E of Rose and
Crown
1936 9999
7 Three
Wheatsheaves
Faraday Road 1800 1910
8 Three
Wheatsheaves
Faraday Road 1910 9999
9 Faraday Road Tollhouse Hill 1800 9999

14. NYPL Building InspectorNYPL Building Inspector
http://leatherwood.herokuapp.com/footprint

15. OHM Current & FutureOHM Current & Future
DevelopmentsDevelopments

16. Summary : OHMSummary : OHM
NowNow
● Ready for sets of 'snapshot'
data
● Temporal data (tags) manual
process
● Routing
● Limited automated rendering
– Existing tools (TileMill) fine for
specific needs
To comeTo come
● More & better examples
– Pre 1800 too
● Integrating temporal tools
into website & editor
– Time-sliders
– Map Warper
● Additional QA tools
● In browser rendering

17. Time SliderTime Slider
● Unifying element for:
– Search
– Editing data
– Viewing data
● Across OHM / Wikimedia
● Prototype work
– Summer 2014 GsoC student
● Date & Period based
● Range or 'Snapshot'

18. More ToolsMore Tools
● Building Inspector
– Ports currently in
progress (with NLS)
● Integration of
MapWarper in editor
● Additional semi-
automated data
capture
● Map Roulette
● QA tools
– Many exist in OSM
– Identify problems to
fix
● Overlapping
temporalities
● Temporal Geocoder

19. Tangible ChallengesTangible Challenges
● Data volumes
● Creating maps (rendering)
● Editing & fixing data
● Imprecise temporality
● Calendars
– implicit proleptic Gregorian
● Buildings
– 3D (some existing OSM work)
– Phased construction
http://demo.f4map.com/#lat=41.8909282&lon=12.4906339&zoom=17

20. Data VolumesData Volumes
● Potential combinatorial explosion of data elements
– Exploration using OSM data suggests not major problem
– Some mitigation routes possible
● Link to wikidata to need for multiple elements
– Name changes
– Historical population
● Urban areas much smaller in past
● Change mainly localised

21. ●
Classifying ChangeClassifying Change

22. RenderingRendering
http://www.openhistoricalmap.org/#map=14/40.7766/-119.2265&layers=H
● Current Approach
– Static Rendering
– Requires new tiles for
each time period
● Future Approach
– In browser rendering
● Vector Tiles
● MapCSS

23. More informationMore information
PresentationsPresentations
– SotM Baltics 2013
Susanna Anas, Wikimedia Finland
– SotM Birmingham
2013
David Evans, U. of Derby
– SotM Karlsruhe 2014
Tim Waters, Topomancy
Blogs etcBlogs etc.
● Wikimaps
Wikimedia Zurich May 2014
Susanna Anas
● Maps Matter
Tartu workshop August 2013
Jerry Clough
Mailing ListMailing List
● https://lists.openstreetmap.org/pipermail/historic/
Monthly Google HangoutsMonthly Google Hangouts
●
Via Susanna ÅnäsVia Susanna Ånäs