“OpenStreetMap is a free editable map of the world
made by people like you!”
AGI NORTH
23 April 2009

About Tim
Tim Waters
Freelance GIS Consultant
and Web Developer
Long time OpenStreetMap contributor & evangelist
Leeds UK
blog: http://thinkwhere.wordpress.com
tim@geothings.net
latest: http:www.MapWarper.net

VGI

VGI
Volunteered Geographic Information (VGI) is the harnessing of tools to create,
assemble, and disseminate geographic data provided voluntarily by individuals
(Goodchild, 2007).
Some examples of this phenomenon are Wikimapia, OpenStreetMap,
and Google MyMaps.
These sites provide general base map information and allow users to create their own content
by marking locations where various events occurred or certain features exist,
but aren’t already shown on the base map.
VGI is a special case of the larger Web phenomenon known as user-generated content.
Straight outa Wikipedia.............there's more pictures later.

Power of Volunteered Geographic Information
1. Potential of VGI to expand/complete/improve existing databases,
infrastructures, & archives;
2. Potential of VGI to enable us to gather/produce new forms of
spatial information that use local knowledge to inform previously un-
answerable questions, unknowable phenomenon, and new social and
political practices. (“new knowledge practices”)

Concerns:
what drives people to do this, how accurate are the results,
will they threaten individual privacy, and how can they augment more conventional
sources
Basics:
Web2 – web search, Google, communities
technologies, GPS cameras, network, computers
Crowd sourcing
price, closed of NMAs (OS licences) Push factor
Openness
Easy
Amateur
---
Future with NMAs etc. Decline in world mapping. Remote sensing and VGI filling in the
gap.
Mapping economically determined. None in developing world. Expensive to keep up to
date.
AND Map2.0

WIKIMAPIA

Google Earth!

http://Geocodr.net
A geocoder that uses k-means
clustering of geotagged images

Flickr Shapefiles

ARGH!!!! Just show me some nice maps

Maps!

You can get the data. downloads.cloudmade.com

Berlin

Copenhagen

Amsterdam

Madrid

NYC

Baghdad

Sydney

Pretoria

Kinshasa

Map what you like

Germany 2006

Germany 2007

Germany 2008

OSM in a nutshell
Most other maps are non-free
Vector data for custom maps is difficult to obtain
licences
Users can improve the map
Fast updates
Commercial maps have intentional errors
Many areas of the world are mapped poorly
Speciality maps
Innovative uses

Mapping data is not free

Not free as in freedom
Maps Copyright
The maps are based upon Ordnance Survey material with the
permission of Ordnance Survey on behalf of the Controller of Her
Majesty's Stationery Office © Crown copyright.
Unauthorised reproduction infringes Crown copyright and may lead to
prosecution or civil proceedings. Luton Borough Council. 100023935, 2006
The Ordnance Survey map data included within this web site is provided by
Luton Borough Council under licence from the Ordnance Survey
in order to fulfil its public function to act as a local authority.
Persons viewing this mapping should contact Ordnance Survey
copyright for advice where they wish to licence Ordnance Survey
map data for their own use

Full of mistakes, car centred

Mistakes cannot be corrected

Cannot re use or reprint

Coverage economically determined

Change happens
inflexible

Katrina

100,000 users
330 million nodes
800million trackpoints
1 Billion Tags

Donate data & free data

Tiger / Line

Other Sources:
Donations
Gaza, people donated to buy
imagery for OSM

Yahoo allow use of imagery

Landsat

http://www.MapWarper.net

Or, just D.I.Y!
Mapping party

Mapping Parties Galore!

Mapping Party Field Trip
7 June Sunday
Patley Bridge

How to do it?
Editors, online.
Do it from home!
Mikels Case Study - Brighton

Case Study:
Mikel in Brighton

Mapping Party, September 2006

OSM Brighton, December 2006

Summer 2007

Winter 2007
Today

Today

1.0

His Process

Download existing data to GPS

Print Out Map for Notes, Bicycle

Network Diagram

Upload GPS Tracks to Computer

Upload Tracks

Draw Over Them

Editing in Potlatch, rollbacks, history

Tech

The OSM-”Tool Chain”
Editors Database Renderer Viewer
Potlatch tiles@ “Google”
API
(Flash) home tiles
(Rails)
Slippy
osmarender, Map
JOSM
pdfatlas, (Open
(Java)
MySQL ... Layers)
“Google”
... Mapnik
planet tiles
dump

RESTful API
http://api.openstreetmap.org/api/0.4/way/35
<way id='7972254' timestamp='2007-09-24T12:36:29+01:00' user='chippy' visible='true'>
<nd ref='59608510' />
<nd ref='59608509' />
<nd ref='59608516' />
<nd ref='59608515' />
<nd ref='59608514' />
<nd ref='59608513' />
<nd ref='59608512' />
<nd ref='59608511' />
<nd ref='59608510' />
<tag k='created_by' v='JOSM' />
<tag k='building' v='retail' />
<tag k='name' v='White Rose Shopping Centre' />
<tag k='amenity' v='shopping_centre' />
<tag k='note' v='huge building' />
</way>

Trackpoints
Nodes

Tags!
amenity = hospital
name = Saint James
POIs emergency = yes
Ways
highway = primary
name = Otley Road
ref = A660
Areas
highway = residential
name = Chestnut Lane
oneway = true
surface = flags
leisure=nature_reserve
http://wiki.openstreetmap.org/index.php/Map_features

simple data format
tagging for metadata
standard map tiles

Volunteers.
OSM donation drive
Over $22,500 raised in 3 days for
new server in early February
Goal was $15,000
servers
api 0.6
downtime

API 0.6
Changesets
user id
version numbers
Diffs can be applied

Licence
Now:
Creative Commons by Share Alike
Future:
Open Database Licence
CC = everything is shared alike
OdbL = only the database should be shared
Both allows commerical use

healthy ecosystem
tools
renderers
editors
routers
applications

Potlatch

JOSM

Merkaartor

Mapnik

ORS

Many mobile apps

Freemap Slovakia & contours

Cycle Map

OpenPisteMap

Open Street Bugs

healthy ecosystem
tools
renderers
editors
routers
applications

Ecology
System
Iteration
Gets better & stronger

Folksonomy
But with standardised conventions.
Voting
mapping reality
proposed
adoption
iteration

landuse=vineyard vs
landuse=farm
crop=grapes

Edit Wars

Taking a leaf.
Tapping the crowd.

Map Maker from Google.

AND Map2.0

Peoples Map (dot dot dot)

Quality
Is it any good?
OSM is sometimes the ONLY source for mapping data
Map Action
Developing World

How good it the data?

− Positional accuracy
− Completeness
− Attribute accuracy and completeness
− Consistency
− Semantic accuracy
− Temporal quality (up-to-date-ness)

http://tools.geofabrik.de/mc/
Map Compare

Dair Grant
Errors in Google / Teleatlas

Errors in OSM
but, they can be fixed :)

OSM 193 bugs per 10km2
Google 89 bugs per 10km2

http://blog.fortiusone.com/2008/12/12/openstreetmap-vs-googleteleatlas-street-coverage/
OpenStreetMap vs. Google/TeleAtlas Street Coverage
The size of the circles are proportional to the values for both, so small circles equal poor coverage
and large circles equal good coverage.
The overlap of the circles shows who appears to be doing better
(orangey/brown showing means that osm is doing better, blue google). OSM is the top layer so a tie will have
OSM looking better, but you can click the layers on and off to see both views of the coverage.

The data is very interesting. Quickly comparing the roads layers against OSM in Kenya show
good correspondence where there is Yahoo aerial imagery to trace against — if OSM had access to the same imagery,
I imagine we’d be pretty much equivalent country-wide. MapMaker is slightly more complete in central Nairobi; I put that down to Google
having full time employees in Nairobi who work on MapMaker
Green = OSM
Purple = Mapmaker

OSM VS OS
Coverage
Blue = OSM better
http://povesham.wordpress.com/2008/08/07/osm-quality-evaluation/
UCL Muki Haklay
http://www.ucl.ac.uk/~ucfamha/OSM%20data%20analysis%20070808_web.pdf

Meridian 2 and OSM – Motorway

comparison
http://povesham.wordpress.com/2008/08/07/osm-quality-evaluation/
UCL Muki Haklay
http://www.ucl.ac.uk/~ucfamha/OSM%20data%20analysis%20070808_web.pdf

Positional accuracy
Area Average
On each tile, 100

difference
points sample with (m)
evaluation of distance Barnet 6.77
between OSM and Highgate 8.33
Meridian 2 New Cross 6.04
South Norwood 3.17
Can see significant

differences: from Sutton 4.83
about 3m to over 8m Total 5.83
http://povesham.wordpress.com/2008/08/07/osm-quality-evaluation/
UCL Muki Haklay
http://www.ucl.ac.uk/~ucfamha/OSM%20data%20analysis%20070808_web.pdf

The analysis shows that, where OSM was collected by several
users and benefited from some quality assurance, the quality
of the data is comparable and can be fit for many applications.
The positional accuracy is about 6 metres, which is expected
for the data collection methods that are used in OSM. The
comparison of motorways shows about 80% overlap between
OSM and OS .
The challenges are the many areas that are not covered –
currently, OSM has good coverage for only 25% of the land
area of England
12 Months ago...
http://povesham.wordpress.com/2008/08/07/osm-quality-evaluation/
UCL Muki Haklay
http://www.ucl.ac.uk/~ucfamha/OSM%20data%20analysis%20070808_web.pdf

Field Trip!
7 June Sunday
Patley Bridge
Tim Waters
http://thinkwhere.wordpress.com
tim@geothings.net
Thanks! Pub?