This has to be one of the coolest stories I’ve ever found. It describes how google and all the other map companies out there know about all the streets on their maps and also how they can give directions to different places. I’ve always wondered how google maps and mapquest knows about exits, streets and where to turn using a gps.
Here’s an excerpt of how it works:
Have you ever wondered where the data for your favorite map-based GPS unit comes from? Who really does all of that work to make sure the road you are driving down doesn’t plunge you off a cliff? Meet Mark Vermeys, a geographic field analyst for Tele Atlas.
If you know anything about GPS devices, you’re probably familiar with Tele Atlas. This international corporation, which has its American headquarters in Boston, provides the GPS data for an array of device manufacturers, such as TomTom, Pharos and Navman, automobile makers including BMW, Ford, Honda and Toyota and Web sites like Google and Mapquest. As many GPS users know, the data available from these sources can quickly become out-of-date, frustrating drivers who turn down a wrong way and end up at a dead end.
Enter Vermeys and the Tele Atlas GPS Mobile Mapping Van.
The Tele Atlas GPS Mobile Mapping Van is a small, but very important part of the GPS data company’s mapping strategy. Drivers like Vermeys comb the United States in these specially equipped vans, hitting highways and side-roads in their quest to make sure you and I don’t end up in a ditch.
The Tele Atlas Van
A typical Tele Atlas GPS Mobile Mapping Van is a converted minivan which sports a roof rack like contraption holding a GPS antenna and four digital cameras. Inside the driver, in this case Vermeys, interacts with an IBM ThinkPad which runs several programs to help him in collecting map data. One program is the existing road data itself, with assigned roads for him to drive during a day. Another program monitors photographs which are taken by the four external cameras every ten meters.