If you've ever wondered where the map data that powers your smartphone or portable navigation device comes from, then you're in luck. Nokia stopped by recently with the new Lumia 822 Windows Phone 8 handset, its new Nokia Maps 3.0 app, and the awesome, street-scanning Navteq True car.
Sitting atop the True car is a pretty impressive bit of data acquisition equipment.
At the top of the tower is an array of cameras that capture a 360-degree street view as the True car rolls down the road. This scanned data is used in the street view that you get when zoomed all the way in on Nokia's Here.net online mapping service or new Nokia Maps Live Sight augmented reality destination search.
Below the first bank of cameras is a rotating Lidar (Light Detection and Ranging) array. This bank of 64 invisible lasers rotates to scan the buildings on either side of the road, objects such as trees lining the road, and the road itself. As the lasers pass over the environment, more than 1.3 million points of data are captured every minute. Using this data Nokia and Navteq are able to capture 3D representations of everything that the True car passes for a variety of uses. The resolution of the scan is so fine that I was even able to see the road markings separating the drive lanes, indicating turn restrictions, and marking bike lanes and fire lanes. Color me impressed.
Moving down the tower, we came to a second bank of high-resolution cameras dedicated to sign scanning. These cameras can read the details on roadside signs, speed limits, and street names. Also on the roof is a differential GPS sensor that tracks the vehicle's location with a much higher precision than your average handheld or in-car GPS receiver. Further down and connected to the rear wheels are a pair of wheel encoders that track how fast and how far the vehicle has driven, adding an extra layer of redundancy and accuracy to the GPS data. These sensors can also determine the grade of the road and its curvature and banking.
The True car is piloted by a local driver to the city being mapped who basically drives down every road in town, scanning and mapping along the way. The driver adds his or her local knowledge of what roads are changing and what roads need additional scanning. The True car can scan the road at the posted speed limit, even at speeds up to 70 mph.
All of that data, millions of Lidar data points, GPS data, and panoramic images are processed by a massive computer in the True car's wagon hatchback and funneled into a 10TB database that's stored locally. At the end of the day, the hard drives containing all of that data are removed and the scanned info uploaded to one of Navteq's three worldwide central processing centers where the raw data is transformed into a full-color, 3D representation of the roads traveled.
The GPS street data, speed limits, turn and lane restrictions, and other 2D data is used in mapping and navigation software, such as the new Nokia Maps 3.0 that I was able to see in action on the Nokia Lumia 822.