Tracing Your Steps

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Dept.: Tech Lesson
Tech: GPS drawing
Tools: GPS receiver, free software
Cost: $100 and up
Dabbler | | | | | MasterLike crop-circle makers and Christo before them, Jeremy Wood and Hugh Pryor are artists who use the landscape as their canvas, tracing miles-long drawings around the British countryside on foot or in a car. Their paintbrush is virtual: a portable GPS receiver that records their coordinates every few seconds, creating a huge connect-the-dots pattern. Later they export that data to a PC, where custom- designed software called GPSograph reveals the shape of the path they traveled.


Sometimes the patterns are naturally occurring—the pair’s first GPS drawing was of a fish they noticed on a map of central England. Others are planned in advance, including the eight-mile-high dollar sign they recently drew in Las Vegas [inset here] or the game of tic-tac-toe they played in
Hollywood. Wood and Pryor didn’t invent GPS-based art—it’s been around since at least the mid-1990s, when the receivers went portable—but they have inspired others to follow in their footsteps. Their site, gpsdrawing.com, houses contributions from fellow GPS artists all over the world.


Follow the instructions below to tromp out your own masterpiece, then send it to h20@time4.com and we’ll post it to a special gallery at popsci.com/h20.


Making Your Own GPS Drawing

I used a wrist-worn GPS receiver from Garmin, the Forerunner 201, to draw the large “H2.0” in Seattle [above], but any GPS receiver that lets you dump data to a PC should work. The software that comes with this unit is called Logbook, so that’s what I’ll refer to in the steps [below]; most programs will have similar options.


1. Install USAPhotoMaps (free at jdmcox.com), which downloads the aerial maps from a free Microsoft service.


2. Look at a map, plan your route, and run, drive, or cycle with your GPS receiver in tow.


3. When you get home, import the GPS data to Logbook. Choose Data Preview to see the path you took and how well it approximates the shape you were aiming for. If you’re satisfied, export the data as an XML file (File > Export to XML).


4. Open USAPhotoMaps and import the data (File > Import
Forerunner Logbook), and save it as a CSV file.


5. In the USAPhotoMaps menu, go to GPS > Display Tracks,
and select the CSV file you just saved.


6. That’s it. You should see the aerial map with your path overlayed.