Making Google Maps from a GPS track

March 5, 2009

It can hardly have escaped most people’s attention that Google Maps is an incredibly useful tool.¬† I just used it to plan my summer holidays, marking where we are staying, places to visit, routes to take and so on. I did this using the My Maps feature, available through a Google Account, which lets you annotate and edit a map. What may not be so obvious to new users is that you can save the map as KML by using the link URL. and adding “&output=kml” to the end.

More interestingly, you can import KML files into My Maps in Google Maps, which adds extra  possibilities. I exploited this when I made a map of the running route for the Red Nose Day Run we are doing. You can see the result at I created this by travelling the route wearing a GPS-enabled watch (the excellent Garmin Forerunner 305), and converting the resulting track record to KML (using a program called Ascent on my Macintosh).

All well and good, but the Forerunner had recorded a point every few metres, and that was too much for me to further edit by hand. I was able to get a much neater result by smoothing the KML using the “simplify” filter of the excellent gpsbabel ( utility. This removed all points which did not make more than 10 metres of difference. Now I could upload the filtered map to Google Maps and refine the route by using it as a KML editor. Now I have to actually run the route – rest assured that we’ll be tracking what we actually do using a variety of GPS tools.

Of course there are a 1001 tools out there for editing KML, making map-based visualizations, plotting routes, and so on. I’m just talking about casual use here. But the extreme ease of performing tasks like this shows that there is no excuse for not getting into geolocating things in your life.

Erewhon staff raising money for Comic Relief

March 5, 2009

March 13th is Red Nose Day in the UK, when people do silly things to raise money for the Comic Relief charity, which works to alleviate poverty around the world.

Not wanting to be left out, staff from Oxford University Computing Services (where Erewhon is based) are going to run around the city visiting every single one of the Oxford colleges. If you’ve ever been to Oxford, you’ll know this is no small job – we think it’ll be nearly 9 miles. Remember that most of us sit at keyboards all day, so we expect to suffer.

Are you willing to help us raise money, dear reader? If so, head off to and look at the details.