Positioning aside from GPS

The question of where a device and so perhaps where the person who owns or uses it is, is going to be more crucial in the future as we get used to and rely on location-based or location-related services.  The natural assumption many people make is the use of GPS systems - and this is unsurprising, given the recent explosion of consumer electronics devices such as TomTom navigation gadgets etc.  But GPS is imperfect and unsuitable in many applications and a number of other technologies are also going to be increasingly important in terms of assisting with 'the positioning problem'. 

Devices such as accelerometers, electronic gyros and digital compasses can also be very important in piecing together the positioning puzzle.  The cost of these small components is relatively small and so they are increasingly being incorporated into consumer electronics gadgets of various sorts.  A digital camera with a picture stabilising feature will use a gyro component for example.  Performing some number crunching on acceleration data can derive velocity of course.  Combined with mapping information and an initial starting point, tracking movement quite accurately is possible, particularly within buildings and underground (for which maps and floorplans are usually readily available).  

In the future, it will be the combination and aggregation of various positioning data, together with the analysis of such data, which will open up many more applications for location-related services.