OpenStreetMap (OSM) is a collaborative project to create a free editable map of the world. Users can add and edit map data by uploading GPS traces or extracting information from other sources like aerial imagery. This data is stored in a central database and can be viewed and edited by anyone on a web map or using desktop editors. The map is rendered from the database using open source tools and can be used freely under an open license. Developers contribute by improving the tools, database, rendering system, and applications that make up the OSM project.

1. The technical overview of
Open Street Map
劉俊宏
louisliu@locomotion.tw

2. What is OpenStreetMap?

3. OpenStreetMap (OSM) follows a similar
concept as Wikipedia does, but for maps
and other geographic facts.
This information then gets uploaded to
OpenStreetMap's central database from
where it can be further modified,
corrected and enriched by anyone who
notices missing facts or errors about the
area.

4. Anyone can freely download and use the
full information for any purpose they like
under an open source license.

5. http//www.openstreetmap.org/

7. Slippy Map, the map viewer.
Potlatch, the online map editor.
Export, export map data to xml data, image, or
embedded html.
Mapper system
Account setting, query other mappers'
information, sending/receiving messages,
upload GPS traces, writing diaries...

8. Slippy Map
Base Layer:
Mapnik
The default map.
Osmarender
The alternative map.
Cycle Map
The map for cycling.
NoName
Fine ways without naming.
Overlays
Data
View OSM data and it's edit history.

9. The Major Component of OSM system

10. Data Source

11. GPS traces, the major data
source of OSM.

12. Upload GPS Traces
http://www.osm.org/traces/tag/Taiwan
If you do not want your GPX points to be
seen by anybody else, DO NOT upload
tracks. `
Must be GPX (gziped or flat) file format.
GPX trace file should consist of track points
with valid time stamp.

13. Other data source
Yahoo! Aerial Imagery
Yahoo! have agreed to let OSM use their aerial
imagery for the purposes of tracing.
It is possible to sketch in the road layout for large
expanses of urban areas, without going there.
Cirerone Mapped Taipei with Yahoo! Aerial
Imagery.
Open Aerial Map
The site is currently offline.

14. Convert from other open map data
TIGER
Tiger, Topologically Integrated
Geographic Encoding and Referencing
system data for US streets, produced
by the US Census Bureau, is a public
domain data source.
AND
Automotive Navigation Data donated
the entire streetmap of the
netherlands.

15. DO NOT
Copy from copyrighted map!

16. Basic Element
Node
Nodes consist of latitude and longitude.
Nodes are needed to define a way, but a node can
also be a stand alone unconnected point.
Standalone nodes should always have at least one
Tag.
Nodes forming part of a way open do not have
tags themselves.

17. Way
A way is an ordered interconnection of at least 2
nodes that describe a linear feature such as a
street, railway, river …
Ways should be split into shorter sections if
different properties exist.
Nodes can be members of multiple ways.
Area (Closed way)
Areas are not separate elements, they are merely
closed ways that represent an area.

18. Relation
A relation can group other elements together,
nodes, ways and maybe even other relations.
Relations can be used to represents things like
cycle routes, bus routes, turn restrictions,
boundaries....

19. Tag
A property attached to a node, way, area or
relation.
These properties are Key-Value pairs describing
the element.

20. To ensure that applications and other users
of the OSM data can interpret the tags in a
meaningful way it is recommended but
not required to follow certain tagging
standards documents.
http://wiki.osm.org/wiki/Map_Features
http://wiki.osm.org/wiki/Tw:Taiwan_road_tagging
http://wiki.osm.org/wiki/tagwatch

21. Key Value
highway tertiary
ref TC-26
name Dama Rd.
name:zh 大馬路
is_in Waipu Township,
Taichung County
is_in:zh 台中縣外埔鄉

22. Editor

23. Potlatch
A Flash based online
Map editor, you can
found at “Edit”tab on
home page.
Potlatch is intended as
as an easy-to-learn
editing environment for
drawing ways and
adding metadata to
existing ways.

24. Merkaartor
OSM Editor for UNIX,
Windows and OS X.
Map view near-
WYSIWYG, anti-
aliased, with road
names.
Live connection to
your GPS.

25. JOSM
Java OpenStreetMap Editor
JOSM is a feature-rich editor.
Highly configurable and extensible via plug-
ins.
Can work off-line using download data files.
Work with local photo and GPX files.
It's POWERFUL but Not Easy to learn.

26. Edit map with GPS tag image.

27. Using Yahoo! Aerial Image as background.

28. ArcGIS Editor for
OpenStreetMap
http://martenhogeweb.blogspot.com/
2010/07/
announcing-arcgis-editor-for.html
http://tinyurl.com/2wgmhu5

29. API and Back End System

30. OSM API
OpenStreetMap has an API for fetching and
saving from/to OpenStreetMap database.
The API is the server component to which
REST requests are addressed. The REST
requests take the form of HTTP GET, PUT,
POST, and DELETE messages. Any payload
is in XML form, using the MIME type
"text/xml" and UTF-8 character encoding.

31. All of the calls to the API which update,
create or delete data have to be made
by an authenticated and authorized
user. Authentication works by using
HTTP Basic authentication using an user
name and password or by using OAuth.

32. ADD/REMOVE/UPDATE elements.
Download data inside a given
bounding box.
Query history of elements.
Retrieving GPS points/traces.
.....

33. Changesets
To make it easier to identify related changes
the concept of changesets is introduced.
Every modification of one or more of the
elements has to reference an open
changeset.
Changesets are specifically not atomic -
elements added within a changeset will be
visible to other users before the changeset
is closed.

34. Changesets facilitate the implementation of
rollbacks. By providing insight into the
changes committed by a single person it
becomes easier to identify the changes made,
rather than just rolling back a whole region.

35. Current Version is 0.6.
http://wiki.osm.org/wiki/API_v0.6
For testing:
http://api06.dev.openstreetmap.org

36. OSM API Server
The Rails port is the current version of OSM's
server code - API, web front end and everything
that runs on www.openstreetmap.org.
Runs on Unix-like systems.

37. Planet.osm
a snapshot of the OpenStreetMap database.
the latest revision of the nodes, ways, relations
and changesets
an XML formatted .osm file.
http://planet.openstreetmap.org/
Current file size: 8.3GB
(Bzip2 compressed, 2010 04/12)
Extrats: partical area of planet.osm
Osmosis and other tools can handle it.

38. Rendering System

39. Mapnik
http://mapnik.org/
Mapnik is a open source toolkit for rendering
maps.
OSM uses Mapnik to render 256 × 256 pixels tiles.
Use Postgres as data backend and import osm
data source to db with osm2sql.
A template.xml controls style sheet.
It's need several hours to generate Taiwan nearby
tiles.

40. mod_tile and rendered
An Apache module which is responsible for
requesting tiles.
renderd - A rendering daemon which calls mapnik
and writes the map tiles to the filesystem
If the tiles are already rendered then Apache will
serve them efficiently from the filesystem.

41. Tile@Home
We all heart SETI@Home.
A Distributed tile render system.
There are many people who run the client
software on their computers that ask what map-
tile to render and contribute their results back to
the server.
Osmarender and http://informatinofreeway.org/
uses T@H.

42. Play with planet.osm and
render style sheet
to meet your need.

43. OpenCycleMap.org

44. Mapper Community

45. wiki.openstreetmap.org
Mediawiki is OSM's document system.
News.
Instructions for Mapping.
License information and other issues.
Development information.
Wiki project pages for mapping different
countries or cities.
References for map features (tags).
A voting system.

46. Contact other mappers
Mail List
OSM-talk, talk-tw, osm-dev......
Send Message
Send message in http//osm.org.
Discussion in wiki's “talk page”
Join local mapper group
Map Party is fun!

47. Open Street Map and Open
Source
Develop tools, Database, rendering
tools... are all open source software.
OSM's applications and sites are also
open sourced.
Fetch the source code:
svn co http://svn.openstreetmap.org/

48. Why use open source
Use open source software to process
open data.
Standing on Shoulders of Giants.
Save data in open file format.
Free from proprietary format.
Users won't buy 'professional tool' to
use the open geography data.

49. To Be A Mapper
Wiki is your friend
Beginner's Guide
Map Features
Editing Standards and Conventions
Mapping techniques
Join local mapper group

50. 2010 08/07 Map Party @Tainan
http://registrano.com/events/b2daeb

51. To Be A Developer
Wiki is your friend
#OSM-dev list.
Read The Find Manual.
Read The Find Source Code.
Observe develop tools' license.
Do NOT break OSM license and policy.
Ask the community for help!

52. Thank you for participation