Navigation by maps?

There are many devices out now which include Global Positioning by Satellite (GPS) technology, and a whole raft of innovative services are being produced which use the location information which it provides.   The European version of GPS, Galileo, should be operational in around five years time.  But satellite based location systems are not always the best approach.  

Inertial systems for tracking location can offer some advantages over the sky based systems.  They may work better in buildings or other shielded locations, and underground.  The accelerometer technology that inertial systems usually rely on can be relatively cheap and reliable for providing location information.  

We often assume that a map is part of the output from devices that help to track people or objects.  However quality maps used as inputs too can provide very accurate data.  Existing map data may be used to qualify the inertial or other positioning information, even in cases where the aim is never to display a map for the user!   And for in-building tracking applications, an accurate plan of where the walls are, the doors and windows etc is often available in the form of architect's drawings!   As Ultra-WideBand (UWB) radio technology becomes common, with the inherent radar-like properties it is capable of at short range, the ability to ascertain position inside buildings will be even more advanced.