GPS tracking works on the same principle like all other types of location tracking: triangulation. Triangulation is the practice of using three different kinds of sensors coming from GPS satellites to measure the distance of an object from each sensor. Them it calculates the relative position of the object based on the location of each sensor. Thus, a GPS locating unit can pinpoint the exact location of a person, an object, or a vehicle which has the GPS receiver or a phone locating device. The location of the target is recorded at regular intervals and can be monitored from a central location where the data sent. These tracking units are basically categorized into three, one of which are data pullers.
Data pullers are a type of GPS tracking units that use GPS technology to determine the exact location of a vehicle, person, or other asset, to which it is attached. As opposed to the other types of tracking units, a data puller is always on and can always be queried when required. They are also called transponders which is a derivative of the words “transmitter” and “responder.” Thus, it has a double function. First, it receives a signal called an interrogator because it is always asking information which is then conveyed as a radio wave at a predetermined frequency. This signal is broadcasted using a different frequency through the built-in frequency converter. Thus, by transmitting and receiving different frequencies at the same time, they can also be detected simultaneously.
Data pullers or transponders were first used during the second World War and attached to an aircraft enabling pilots to send confirmation to radar operators that they were friendly aircraft. Nowadays, they are also used not only in military aviation, but also commercially to send altitude information to the control tower as well as increase aircraft visibility on the radar.
In everyday life, data pullers come in the form of transmitters mounted on car dashboards and are used for electronic tolling systems. Newer car models are also equipped with similar technology that enables it to be easily located in case of emergency. This can also be found in mobile phones in the form of a microchip which sends the phone’s location when dialing an emergency number.