What is vehicle tracking?
A child of the Space Race
GPS was a child of the ‘space race’ between the USA and the USSR. Following the launch of the first artificial satellite, Sputnik in 1957, researchers noticed that the frequency of signals coming from the satellite to a fixed point on the ground increased as it approached over the horizon and decreased as it moved away. This is called Doppler Shift and showed that if a satellite location could be determined from the ground via the frequency shift of its radio signal, then the location of a receiver on the ground could also be determined by its distance from a satellite. The accuracy of the ground location could be improved if signals from two or more satellites could be received and this led to the development of ‘Transit’, a constellation of 36 low earth orbit (LEO) satellites launched in the 1960s and operated by the US Navy for the purpose of submarine warfare.
The introduction of Navstar
The falling cost of chipsets
The arrival of mobile packet switched data
Ever evolving technology
Of course, neither GPS nor GPRS have stood still. There are now more satellite services, not only those launched by the USA, collectively these are known as GNSS (Global Navigation Satellite Systems) and include:
- GPS (USA)
- Galileo Europe)
- GLONASS (Russia)
- Beidou (China)
There are also two regional systems offering coverage in Japan (QZSS) and India (IRNSS).
Mobile phone networks have also developed of course with the evolution of 3G, 4G and 5G. All of these provide digital data links between the vehicle tracking device and the internet.