GPS Trackers and Mobile Phone Tracking


Location tracking equipment, such as GPS trackers and GSM trackers, are useful spy gadgets used for locating someone or something. They come in a variety of shapes, sizes and types. Different types of tracker are suitable for different applications depending on the type of accuracy and range required.

There are essentially three different types of tracking equipment, radio frequency (RF) trackers, GSM trackers and GPS trackers. RF trackers are used for short-range tracking up to several hundred metres. GSM trackers exploit the mobile phone networks and can be located from anywhere in the world, however they only give accuracy to around 50 metres. GPS trackers can also be located from anywhere in the world and be accurate up to 5 to 10 metres.

Radio Frequency Trackers

RF Tracking Device

These trackers transmit a radio signal at a specific frequency that can be tracked using a dedicated receiving device. The receiver uses a directional antenna to determine the direction of the tracking device. By comparing the relative signal strength of the radio signal from a range of different directions, the receiver chooses the direction with the highest associated signal strength as the direction of the tracker.

Radio frequency trackers tend to be small and low power transmitters but require receivers with large directional antenna to detect the signal. This does mean that the transmitters are easily concealed. Incidentally this type of tracker is often used to track animals in animal conservation.

GSM Trackers

GSM (Global System for Mobile Communications) trackers utilise the mobile phone network to approximate the location of the tracking device. Since the location of the mobile phone network towers are known, the location of the tracking device can be determined by cross-referencing which network towers the tracking device can connect to.

If three or more network towers are within range of the tracking device, an accurate location can be determined to within 50 metres. However if there are only one or two towers within range of the tracking device, such as in rural areas, the accuracy is limited to a few hundred metres.

GSM Tracker

GSM trackers are essentially cut down versions of a mobile phone. There are many different mobile phone tracking services available on the web that allow you to trace a mobile phone from anywhere in the world. These tracking services are used for locating GSM trackers too.

To comply with UK law, mobile phone tracking services must be able to confirm that the mobile phone owner has given consent for their mobile phone to be tracked. The tracking company achieves this by sending a message to the mobile phone being tracked (strictly speaking, to the SIM card in the mobile phone). This message must be replied to from the mobile phone being tracked. This is an opt-in process just as you would see when subscribing to a newsletter on a website.

It is against the law in the UK to track a mobile phone without the owner’s consent unless you have a warrant issued by a UK court. Typically it’s only the police and government agencies who are able to obtain a warrant.

GPS Tracking

A GPS (Global Positioning System) tracker calculates its position using four or more GPS satellites. The tracker uses location and timing information from the satellite to calculate a user-friendly location on a map. The satellites are constantly transmitting location and timing information. As a GPS tracker changes location, the satellites it can receive also changes. This means that GPS tracker receives different location and timing information, allowing it to calculate its new location.

There are two different types of GPS tracker, namely GPS loggers and real-time GPS trackers.

GPS Logger

GPS loggers are usually much simpler devices than their real-time GPS tracker counterparts. GPS loggers record location information to an internal memory device. The GPS logger records location, timestamp, direction and speed information. This information can be retrieved at a later date by connecting the GPS logger to a computer. The computer is then able to “play back” the recorded data to show the journey taken by the GPS tracker on a mapping tool such as Google Earth.

Real-time GPS Tracker

Real-time GPS trackers relay its location, timestamp, direction and speed information back to a central server so that the tracker can be monitored remotely. This information is usually sent back using GPRS (General Packet Radio Service) over the mobile phone networks. The central server can usually be accessed via a webpage, which overlays the location of the GPS tracker on visual map. The user is able to watch the real-time GPS tracker as it moves on the map.

Both types of GPS tracker need to have GPS satellite reception. The real-time tracker additionally needs mobile phone reception. GPS satellite signals are often quite weak, it therefore there are limitations where you can conceal a GPS tracker. For this reason, most real-time GPS trackers come with external aerials to help obtain optimal satellite signals in.

Legalities of Tracking

As with most other forms of surveillance, tracking someone without their consent is illegal. Employers can legitimately track vehicles used for work purposes, but this may require their employees to sign a legally binding contract.