How does GPS work?

TomTom Education

Digital maps

How does digital mapping work?

Keeping digital maps up to date
There are 3 main ways to collect the data to develop and update digital maps:

1. Fieldwork. Data collectors driving the road networks of the world, recording changes and discrepancies.
2. Analysis of aerial and satellite imagery.
3. Customer feedback. At TomTom, for example, any map feedback from customers via the website are reported to TeleAtlas, who look into every single case and , where appropriate, actually send inspectors out to physically check the locations.

Digital mapping is a time-consuming and logistically challenging process. So a company like TeleAtlas is constantly developing new technologies and practices to increase the speed and comprehensiveness with which their maps are updated.

Take fieldwork. TeleAtlas have now also developed mobile mapping systems.


Mobile Mapping systems – a little bit James Bond
Mobile Mapping vans are equipped with up to six high-resolution digital cameras, with at least one pair operating stereoscopically. This means that two cameras are spaced apart, so that their combined images provide 3-D information.

The vans also carry a differential GPS receiver, fibre-optic gyro, odometer and up to 4 PC’s equipped with tailor-made programming to process data on board.

It means TeleAtlas can build up a library of information and, more importantly, that your TomTom maps are updated to reflect changes in the real world as soon as possible after they occur.

One measure of this is the fact that over half the feedback of map discrepancies TomTom now receives from customers have already been resolved before the complaint arrives.


More map for your megabyte
But the basic principles of mapping have never really changed. Whether they were using drawings or sea shells, the earliest map makers were effectively compressing information about the real world onto something thousands of times smaller than that real world. The difference is scale.

What makes digital mapping viable is the efficiency with which data is compressed. We tend to become very blasé nowadays about technological achievement, but if you stop to think for a minute, it is quite amazing that you can have all the roads of Europe contained on a card the size of your thumbnail.


The future of digital mapping
There are probably two main areas where advances are being made in ways that are important to make getting from A to B even easier.

The first is in the quality of the maps themselves. Enhanced visualisation should enhance your driving experience. In particular areas like 3D, elevation models and landmarks, have enormous potential.

The other is in a technology called 'incremental updating'. Basically this means that only that part of the database that is added, deleted or modified, is handed onto you; the map user. Which could help greatly in the constant battle to reduce the delay between changes occurring out there on the roads and those changes appearing on your map.

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