How does GPS work?

Organisations might wish to know what their employees are doing and where they are during their working day. There are many reasons for this. Why might the police and a bank want to use GPS? The Police Force will want to know where its officers are so that they can be sent quickly to an incident. A bank will want to know where security staff delivering money to its branches are at all times so that the money is safe. A local council will want to know where its workers are if they are carrying out council duties because the council has a ‘duty of care’ to ensure that its employees are safe. Introduction

The Global Positioning System (GPS) is a satellite-based system used by GPS receivers to find positions and times anywhere on the surface, or near to the surface, of the Earth. GPS uses four satellites for accurate position finding by the GPS device. The time and position information of each satellite is received by the device via signals from the satellites and used by the device to calculate its position on the surface of the Earth. GPS tracking

Step by step animation Second walk through Add satellites one by one! NASA talk Animations showing how GPS works!

GPS is accessible and free to anyone who has a receiver and can be used for navigation to or from anywhere that has a line-of-sight ‘view’ of four or more satellites. GPS tracking uses the data from GPS satellites to find the precise location of the GPS tracking device. For example: if the device is attached to a car, the location of the car can be found; if it is held by a person, then that person can be found; or if the device is in a smartphone, then the phone can be located. Who can use GPS?

Company vehicles or laptops can be tracked by fixing a GPS tracking device to them. People can only be tracked if they carry, and/or have attached to them, a GPS tracking device. Some smartphones have GPS tracking built-in but most mobile phones, while they often have GPS receivers installed, do not have a tracking device. However, the location of a mobile phone can be traced to the nearest mobile phone access point – the place where it was last connected (but not necessarily used) to the mobile phone system. Uses of GPS tracking

The SpyLamp looks like a rear-mounted bike light but contains an anti-theft web-enabled tracking device According to Immobilise, the police-backed property register, a bicycle is stolen every minute in the UK and less than 5% are ever recoveredbicycle is stolen every minute in the UK A mobile phone, vibration sensor and GPS chip are all crammed inside what looks like – and even works as – a rear bike light.GPS You mount it on your bike and it beams its location back to you if it senses movement – such as a bike thief carting it off, but – hopefully – not someone bumping into it as they lock theirs next to it. It keeps doing that until it's disarmed or runs out of power. He "stole" my bike at a prearranged time and place and took it on a jaunt around the city while I went for a coffee. Using my iPhone and the tracking website I could follow the red line that appeared on the map and see where he was with only a minute or two delay. If he stopped for more than five minutes the device would turn off, and if he jumped back on it would fire up again thanks to the motion sensor.

1 Describe at least two uses of GPS tracking in a smartphone. 2 Describe at least two other uses for GPS tracking 3 Write a SIMPLE explanation of how GPS works, aimed at a primary school student. 4 Can you think of more uses for GPS? Hint: GPS receivers are getting smaller and smaller and use less and less power..... All the materials for this lesson are in: Pupils / ICT/ Cambridge Nationals unit 1 / gps Exam-type questions