Misconceptions About The Global Positioning System (GPS)

•  Jonathan Davies
•  David Cottingham

We have spent significant amounts of time studying GPS units and their performance, both in the literature and by practical experiments. It therefore pains us to regularly find news articles where journalists have a woefully inadequate understanding of the basics of this location technology. Below, we give links to various articles where this is the case, and briefly outline what the truth actually is. See also  10 Myths About GPS.

"Satellites Track You"

• BBC:  'Pay-as-you-go' road charge plan "Every vehicle would have a black box to allow a satellite system to track their journey"

Satellite positioning systems do not track the positions of receivers. Receivers infer their position by listening to multiple satellites, and measuring the difference in the amount of time the signals take to travel from each satellite to the receiver. Hence, whilst black boxes might contain a technology to transmit the inferred position to another system, this has nothing to do with the satellite system. It should also be noted that road user charging systems, as mentioned in this article, do not necessarily require the government to track vehicles in real-time.

"GPS is a Privacy Risk"

• Public CIO:  A better sense of where you are "GPS is really custom-made for stalking"

The GPS is a system that allows a receiver to infer its position. That position is not known to the satellites orbiting the earth, or in fact to anyone else, unless the receiver uses some other technology to transmit that position to somewhere or someone else. Hence, one cannot stalk someone solely because they are using a GPS receiver.