Category: maps

Keeping Fit = More accurate maps

My fiancée, Aimi, recently persuaded me to run the Bupa London 10K with her and as it’s only about 7 weeks away we are now having to train every other night. I’ve never been a particularly good runner and, if I’m honest, I find running pretty boring. However, using a GPS device I have found a way to motivate myself and give each run a greater sense of purpose.

The Open Street Map is a project that aims to create a free and editable map of the entire planet. They rely on volunteers, such as me, to create GPS tracks, and then for us to add and edit details on the map.

Now when we go for a run, I take the GPS with me and record the track we take. When we get back home I can then upload the track to my computer and using the JOSM map editor I can literally draw the roads straight on to the map.

OSM currently has good coverage of the main roads and motorways, but it lacks data for a lot of residential areas. So now, through my running, I am gradually mapping the residential roads of Farnborough.

Before

After

The estate I live on was only built a year or two ago and because of this it doesn’t yet show up correctly on any of the major map providers (which is a pain when getting some delivered!). This means that, thanks to my recent contributions, Open Street Map now has the most accurate map for our particular area.

If you extrapolate this trend a few years in to the future (when all existing roads have been covered) it is easy to conceive a time when OSM will be the most accurate map around. Think about it: residents of a new estate are a lot more motivated to ensure that it appears correctly on the map than the traditional map suppliers, and with OSM this process is easy.

Once this happens, delivery companies will start using it, and possibly even contribute to the project as well (a little investment of time by UPS / Tesco uploading their delivery tracks, could save their drivers a lot of time). So simply put, I think Open Street Map is the future of mapping.

Incidentally, if you would like to sponsor me on my run then you can do so here.

Google launches “My Location” – bring on the blue dot

As many blogs have been reporting today, Google has launched a new feature for their Google Maps for Mobile service called “My Location”.

My Location is simple; it shows a little blue dot on the map to represent your current location. However, the really clever part is that GPS is not required for this to work.

Google are able to calculate your approximate location by reading which cell tower (that’s mobile phone mast to UK readers!) you are connected to, and then looking up the co-ordinates of this tower in a central database.

I tested it out at home and it plotted me on the map to within 1700 metres of my actual position. If you do have GPS then it works even better. Enabling GPS on my N95 improved the accuracy of the blue dot to within 60 metres.

Geo-locating Cell Towers

The process of geo-locating the phone masts / cell towers is fairly simple. Each mast will have a unique identifier (such as a MAC address), so all you need is a GPS/GSM enabled device that records the signal strength and co-ordinates as it passes each mast. With a few samples you can then triangulate the approximate position of the mast.

Here are a few of the projects I found that are attempting to geo-tag wireless networks:

  • Intel have been running a research project for a while called placelab, whose aim was to build a database of locations for WiFi access points and cell phone towers.
  • A community based project called WiGLE is concentrating purely on 802.11b networks and has currently over 12 million access points in its database!
  • GSMLoc is an open source project that aims to locate GSM towers all over the world.

At this point it’s not clear where Google got their database, but it seems to be fairly comprehensive!