A GPS tracking unit is a device, normally carried by a moving vehicle or person, that uses the Global Positioning System to determine and track its precise location, and hence that of its carrier, at intervals. The recorded location data can be stored within the tracking unit, or it may be transmitted to a central location data base, or Internet-connected computer, using a cellular (GPRS or SMS), radio, or satellite modem embedded in the unit.
This allows the asset’s location to be displayed against a map backdrop either in real time or when analysing the track later, using GPS tracking software. Data tracking software is available for smartphones with GPS capability.
GPS tracking unit architecture
A GPS tracker essentially contains a GPS module to receive the GPS signal and calculate the coordinates. For data loggers it contains large memory to store the coordinates, data pushers additionally contains the GSM/GPRS modem to transmit this information to a central computer either via SMS or via GPRS in form of IP packets.
Types of GPS trackers
Usually, a GPS tracker will fall into one of these three categories, though most GPS-equipped phones can work in any of these modes according to mobile applications installed:
A GPS logger simply logs the position of the device at regular intervals in its internal memory. Modern GPS loggers have either a memory card slot, or internal flash memory card and a USB port.
Data pusher is the most common type of GPS tracking unit, used for asset tracking, personal tracking and Vehicle tracking system.
Also known as a GPS beacon, this kind of device pushes (i.e. “sends”) the position of the device as well as other information like speed or altitude at regular intervals, to a determined server, that can store and instantly analyze the data.
GPS data pullers are also known as GPS transponders. Unlike data pushers that send the position of the devices at regular intervals (push technology), these devices are always on, and can be queried as often as required (pull technology). This technology is not in widespread use, but an example of this kind of device is a computer connected to the Internet and running gpsd.