This document discusses OpenHistoricalMap (OHM), which aims to create a map of everything that has ever existed by adding a time dimension to OpenStreetMap data. It provides background on OHM and outlines the technical stack used, including the website, editors, database replication, tile generation, and potential areas for future work like improved time-based querying and interfaces. The speaker encourages participants to get involved in further developing OHM through activities at an upcoming hack day.

1. Tim Waters
Tech Changes to the
OpenStreetMap Stack

2. OpenHistoricalMap.org
● Very modest, really...
●
● A map of everything that has ever existed.
● It's putting a time slider on the world
● It's the worlds most out of date map.

3. What it isn't (quite)
Histosm

4. What it isn't (quite)
Historical Objects in OSM

5. What it is

6. Background

7. Many peoples mind
Slow start
Immense interest

8. Examples

9. Hunterston Scotland 19C

10. Hunterston Scotland Now

11. Saeby – Denmark 19C

12. Saeby – Denmark Now

13. Roman Roads

14. Roman Mainz

15. WW1 Trenches

16. Snows Infected Pump

17. Snows Infected Pump

18. Snows Infected Pump.. in OSM

19. Seattle – Jeff Meyer

20. Burning Man 2008/9

21. Manhattan 1854

22. Manhattan 1854 - Digitzer

23. NYPL Building Inspector

24. Data!

25. How to add stuff to OHM

26. Imports and tracing
Historical maps

27. Wikimaps

28. Wikimaps

29. Wikimaps

32. Editing
● JOSM – change URL
●
● Embedded iD editor
●
● Tags – start_date end_date
● (note of source map would be nice)

33. Simple?
● see frankies presentation
● cart before horse?
● osm way- good enough is best.
● Led by contributors not historical GIS “experts”
● Do whatever and let the rendered sort it out!

34. Stats
292 users
1,711,788 Ways
106,718,875 Nodes
6 planets so far 1.2G uncompressed

35. THE STACK
● What is the stack
● Website / API
● Editors
● Database export / changes replication
● Overpass API
● Map tile generation

36. Website
vagrant up && vagrant ssh
rails s

37. Embedded id Editor

38. Database / Replication
osmosis -q --replicate-apidb
authFile=dbAuth.txt
validateSchemaVersion=no
--write-replication
workingDirectory=data

39. Overpass
http://overpass.openhistoricalmap.org

40. Map Generation
Get a bit techy

41. OSM2PGSQL
osm2pgsql --slim
-S ohm_style.style
--tag-transform-script
ohm_tags_transform2.lua
-d ohm_gis -C 16000 --number-
processes 4 ohm.osm

42. OSM2PGSQL
-S ohm_style.style
node,way start_date date linear
node,way end_date date linear
node,way start_date_year int4 linear
node,way end_date_year int4 linear

43. OSM2PGSQL
--tag-transform-script
ohm_tags_transform2.lua
https://lists.openstreetmap.org/pipermail/dev/2013-May/026933.html
Kai Kruger
The lua script you pass into osm2pgsql needs to implement 4 functions
function filter_tags_node
function filter_tags_way
function filter_basic_tags_rel
function filter_tags_relation_member

44. OSM2PGSQL
--tag-transform-script
ohm_tags_transform2.lua
-- dates have to be ISO 8601 format YYYY-MM-DD
-- since postgres only goes as far back as 4713 BC, we'll store the
year in a new key
if (keyvalues["start_date"] ~= nil ) then
year,month,day = nil
year = string.match(keyvalues["start_date"], "^(-?%d+%d%d%d)")
if (year ~= nil) then
y, month = string.match(keyvalues["start_date"], "^(-?%d+%d%d%d)-
(%d%d)")
if (month == nil) then
month = "01"
day = "01"
else
y, m, day = string.match(keyvalues["start_date"], "^(-?%d+%d%d
%d)-(%d%d)-(%d%d)")
if (day == nil) then
day = "01"
end

45. --because I suck at patterns!
year = string.sub(year, 0, 4)
month = string.sub(month, 0, 2)
day = string.sub(day, 0, 2)
end_date = year.. "-" .. month .. "-"..day
keyvalues["end_date"] = end_date
keyvalues["end_date_year"] = year
else
OSM2PGSQL
--tag-transform-script
ohm_tags_transform2.lua

46. Maps
Database
Create view
create view planet_osm_line_2008 as
select * from planet_osm_line
where start_date_year = 2008;
insert into geometry_columns...
'planet_osm_line_2008'

47. Maps
CartoCSS / Mapnik project uses views
"Datasource": {
"type": "postgis",
"table": " (select way,waterwayn
from planet_osm_line_2008 where waterway in
('stream','drain','ditch') and (tunnel is null or
tunnel != 'yes') ) as water_lines_casing",
"extent": "-20037508,-
19929239,20037508,19929239",
"key_field": "",
"geometry_field": "way",
"dbname": "ohm_gis"
},

48. mod_tile
By Jaimie ohm_mod_tile
Needs review!

49. Future
● Overpass to do date time queries
● iD filtering - regex on year? time slider
● mod_tile review to propagate down a date range
to tile set
● Use Vector tiles and just use styles for date
queries?
● Front end js vector rendering?
● Mapwarper / wikimaps UI improvements

50. Join In & hack day activites?
● Overpass to do date time queries
● More map layers (19C, 18C, Roman)
● iD filtering - regex on year? time slider
● mod_tile work review
● Use Vector tiles and just use styles for date queries?
● Front end js vector rendering
● Mapwarper / wikimaps UI improvements
OpenHistoricalMap.org
#ohm on irc.oftc.net
https://lists.openstreetmap.org/listinfo/historic
https://github.com/openhistoricalmap/