FrOSCon: OpenStreetMap presentation by Andy Robinson - mrtopf.demrtopf.de

FrOSCon: OpenStreetMap presentation by Andy Robinson

This talk was given by Andy Robinson at FrOSCon who is the secratary of the OpenStreetMap Foundation at the moment.
The Foundation is just for promoting the project not for controlling it. The control is pretty much in the community’s hand.

You can find it here.

Why OpenStreetMap?

looks like Google etc. but:

  • first: it’s wiki based, full history of every edit is there
  • wiki also means: There is something not on the map you’d like to see, you simply add it
  • since it’s your data, you can do what you like with it!
  • you can take data in whatever data, render it as you like, create an application etc.
  • unlike Google Maps or others (TeleAtlas etc.) the map data is not restricted. You are stuck with that one view Google provides.
  • with Google and the likes it might also take a lot of money to get direct access to the data
  • it runs since 2004, data is added from 2005 on. So quite a lot of data added already in only 3 years

There is another reason: Why not?

License

  • released under a CC license Share Alike 2.0 Generic
  • but they have a problem because this license does not cover this type of data
  • difficulties also with giving attribution as there are thousands of contributors
  • Goal: A special license tailored for use with map data

What’s under the hood?

It’s a huge big bin full of data:

  • 57,000 registered users (doubling every 5 months)
  • 11.5% users actively in mapping each month
  • 20 million kilometers of highway
  • 1/2 million places (cities, towns, village, …)
  • 425 million GPS points
  • 282 Million geographical elements
  • history of every edit

All stored in MySQL. It’s already bigger than wikipedia in terms of data size.

Similar questions like wikipedia:

How reliable is the data is a common question.
Answer: It is easily verifyable and not subjective data, so the data is more reliable.

Real Time Data

There is a RESTful API which talks mainly XML. Behind that is Ruby on Rails talking to the MySQL database backend.

Other Services

  • Planet file XML file & diffs (several GB compressed). You get diffs up to a minute
  • Map Tiles
  • Mapnik Tiles
  • Tiles@Home (Osmarender) Tiles. Takes XML through a stylesheet, turns data into SVG.
  • Namefinder (search facility to find places)
  • Data Browser (look at individual components of the data, like edits etc.)
  • Map export (raster/pdf/xml)
  • dev server (separate server for developer)

Software

  • Data Editors
  • Online (Potlatch, Flash) and Offline (JOSM, Java)
  • Map display – OpenLayers (JavaScript)
  • Osmarender (see above) XSLT -> SVG
  • perl, python and other stuff abounds
  • Many satellite projects and ideas developed

Interests

  • Cartography
  • Environmental issues
  • Humanitarian and disaster relief (in order to go into an area with very simple equipment and quickly create a map)
  • Navigation and routing (esp. as mobile devices now get GPS)
  • Mobile apps (several devices can show OSM maps)
  • Games (more in the future)

Ok, So Let’s Go Mapping

What we need:

  • reflecting jacket (in order not to get stupid questions)
  • GPS device
  • photo camera to shoot where you’ve been
  • some transportation means (bike etc.)

You then run around and you upload your data as a GPS trace.

You then edit it in the editor and might see many routes on top of each other. The online editor written in Flash also shows aerial images from Yahoo (they have an agreement with Yahoo to be allowed to use that but the problem is that Yahoo has not a lot of such images). Another source in the UK is out-of-copyright mapping by using old maps. But this is of course out of data for e.g. housing areas.

Tagging

Tags habs a structure but no standard. Examples: highway=motorway, amenity=school, access=anlieger_frei, horse=yes.

Most important tag: amenity=pub

Rendering

One way is to use OSMARENDER to turn data into SVG. You can of course change the stylesheet as you like (different colors, etc.).

Example for different type of rendering: A bicycle map which highlights things differently.

Data Viewer: Shows the nodes, the tags, the recent history etc. This can also retrieved by using the REST API.

Other uses

Mapping Parties and other activities

Mapping Parties are gathering of OpenStreetMap people to map an area which hasn’t been mapped before. There are also hackdays for working on the software.

Communication

Coding

svn.openstreetmap.org
trac.openstreetmap.org

All the developers have done some mapping work, if you don’t like it probably coding for it is also not for you.

Questions

What about height data? Is the GPS information imported?

No, it’s not as it’s not very accurate. There are people working on getting such data in though.

If map data would be available freely, wouldn’t this project be obsolete?

This wouldn’t negate OSM at all because it just enables more. AMD for instance gave data about the netherlands which was quite good quality but not complete. So it’s benefit. OSM also puts pressure on institutions to release their data to the public domain or at least some usable license.

How much does the GPS device cost?

The device I have costs about EUR 180,- as it also displays OSM data as well. One can enter just cheaper than that which only logs. Of course you can also just use your mobile phone if it has GPS or you get a GPS receiver for it.

What about house numbers?

There is a lot of debate about it (how to encode it etc.). The main question was: Should the house number on the physical house or should it be on the street (easier for routing but problems with moving). There is a schema on the wiki which is mostly used. But house number data is just starting.

Comment: Going out mapping is great for actually going out and also learning about the area you are living in.

Do you have any problems with spam/vandalism?

It’s easy to spot as it didn’t look right. But not a big problem.