How does GPS vehicle tracking work?

The majority of vehicle tracking systems now use GPS (Global Positioning System) to accurately locate a vehicles position. This article provides an overview of how GPS vehicle tracking works including a brief history and overview of GPS itself.

A GPS tracking system uses a small device that has an onboard GPS receiver. When this device is installed into a vehicle it receives frequent transmissions from multiple GPS Satellites. The GPS device uses the data received from the GPS satellite to accurately locate its real time position (calculated in longitude and latitude). This information is then sent from the tracking device via the mobile phone network (GSM/GPRS) to a secure server. The relevant information is made available through the internet to the user via their vehicle tracking application.

How does GPS work?

All GPS satellites simultaneously transmit repeated signals detailing the time and their current location. These GPS signals travel at the speed of light and depending on the distance of the satellites from the receiver the signals will arrive at slightly different times. The GPS receiver than estimates its distance from each satellite based upon the time it has taken to receive the signal. The longitude, latitude and altitude of the vehicle can be calculated once the data from a minimum of four satellites has been received. Time precision is crucial for the accuracy of GPS and therefore all GPS satellites have an atomic clock onboard.

A minimum of 24 satellites are always in operation and due to the arrangement of the orbit paths this means that there are at least four satellites in line of sight at any location on Earth, at any time. Each GPS satellite orbits the Earth once every 12 hours at an altitude of 12,600 miles travelling at around 7000 mph.

GPS was developed by the United States Department of Defence and was intended for military use. Civilian access was granted in 1983 by US President Ronald Regan with a downgraded accuracy of +/- 100 metres. However, consumer grade GPS access has benefited since the year 2000 from the lifting of this restriction and now has an accuracy of +/- 10 metres, compared to the survey grade accuracy of +/- 10mm. The GPS system is still funded and maintained by the United States Department of Defence. The European Union is currently scheduled to launch a Global Navigation Satellite System by 2013. This system will be called ‘Galileo’.

Although GPS was originally developed for military purposes its uses have now been realised in a number of different applications such as land surveying, map making, navigation and vehicle tracking.

Improvements in GPS tracking means that companies are able to receive more detailed information where required, improving their ability to make informed decisions regarding their fleet of vehicles. Vehicle tracking can also be used to improve customer service and help ensure that employees are driving responsibly and conforming to duty of care legislation.

GPS vehicle tracking has become more affordable allowing companies of all sizes to benefit from the cost savings and operational efficiencies that installing a tracking system can bring.