Who creates digital maps?

Nokia recently demonstrated its new 6110 Navigator phone to PC Authority. In essence, it’s a 3G phone that includes GPS. Unlike the 330 and N95 that came before it, the 6110 Navigator is Nokia’s first 3G handheld to include full turn by turn navigation.

The GPS mapping data is provided by Navteq, a company that also provides the in car navigation system for General Motors and Peugeot. Representatives from Navteq gave us a ride in their mapping cars to demonstrate how they plot road data and points of interest (POIs).

The Navteq mapping data is captured using a differential GPS receiver; a more accurate version of a standard GPS receiver thanks to additional position correction circuitry. Differential GPS needs to be licensed from the government, and the error correction technique the system uses requires the use of a signal broadcast as part of the Triple J RDS subcarrier. The advantage is that it is accurate to within 50 centimetres (as opposed to standard GPS, which can be accurate from one to ten meters depending on atmospheric conditions), and it provides both coordinates and a clock pulse to a laptop.

The pulse cycles at 1Hz and is also used by the laptop to capture images from a camera mounted below the rear view mirror every second with the reception of GPS coordinates. Navteq is currently mapping European roads with the aid of six roof mounted cameras which produce a similar image to Google’s street view, and plans to use the same system on Australian roads in the future.

All roads are plotted by driving through them, and subsequent drives have live coordinates layered over Navteq’s existing maps in real-time. Any changes, such as roundabouts replacing intersections, are tracked by the computer operator. The driver would then circle the roundabout to map out the changes in the road and then verify the new information against the photographs back at base. This new information is then muxed back into the database and rolled out as part of the next update.

Even though Navteq buys the rights to several government POIs, the process is surprisingly labour intensive. Almost all points of interest are entered manually, including restaurants, petrol stations and local street rules. The system has the capability to apply local street rules to different vehicle types. For instance, a street that is off limits to heavy vehicles would receive a database entry that would make the route inaccessible to trucks.

The Nokia 6110 Navigator ships with Australia wide maps, and is available now.