A GPS tracking unit is a device that uses the Global Positioning System to determine the precise location of a vehicle, person, or other asset to which it is attached and to record the position of the asset at regular 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), 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 customized software. The Global Positioning System (GPS) is currently the only fully functional Global Navigation Satellite System (GNSS). ... A cellular network is a radio network made up of a number of radio cells (or just cells) each served by a fixed transmitter, normally known as a cell site or base station. ... General Packet Radio Service (GPRS) is a mobile data service available to users of GSM mobile phones. ... An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ...

Types of GPS trackers

Usually, a GPS tracker will fall into one of these three categories:

Data loggers

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 and a USB port to act as a USB flash drive. This allows easy downloading of the data for further analysis in a computer. Data logging is the practice of recording sequential data, often chronologically. ... Four major types of memory cards (from left to right: CompactFlash, Memory Stick, Secure Digital, and xD. A memory card or flash memory card is a solid-state electronic flash memory data storage device used with digital cameras, handheld and laptop computers, telephones, music players, video game consoles, and other... A USB flash drive. ... Note: USB may also mean upper sideband in radio. ... A USB flash drive, shown with a 24 mm U.S. quarter coin for scale. ... This article is about the computer terms. ...

These kind of devices are most suited for use by sport enthusiasts: They carry it while practising an outdoors sport, e.g. jogging or backpacking. When they return home, they download the data to a computer, to calculate the length and duration of the trip, or to overimpose their paths over a map with the aid of GIS software. GPS devices are also integral tools in geocaching. Jogging is a form of trotting or running at a slow or leisurely pace. ... Backpacking is traveling long distances with a backpack. ... A geographic information system (GIS) is a system for managing data that has a spatial specialized form of an information system. ... This article or section does not cite any references or sources. ...

In the sport of gliding, competitors are sent to fly over closed circuit tasks of hundreds of kilometres. GPS loggers are used to prove that the competitors completed the task and stayed away from controlled airspace. The data stored over many hours in the loggers is downloaded after the flight is completed and is analysed by computing the start and finish times so determining the fastest competitors. A modern glider crossing the finish line of a competition at high speed. ...

Data pushers

This is the kind of devices used by the security industry, which pushes (i.e. "sends") the position of the device, at regular intervals, to a determined server, that can instantly analyze the data. This article needs additional references or sources for verification. ... It has been suggested that this article or section be merged with Push media. ... This article or section does not cite any references or sources. ...

These devices started to become popular and cheaper at the same time as mobile phones. The falling prices of the SMS services, and smaller sizes of phone allowed to integrate the technologies at a fair price. A GPS receiver and a mobile phone sit side-by-side in the same box, powered by the same battery. At regular intervals, the phone sends a text message via SMS, containing the data from the GPS receiver. “SMS” redirects here. ... Over fifty GPS satellites such as this NAVSTAR have been launched since 1978. ...

The applications of these kind of trackers include:

• Fleet control. For example, a delivery or taxi company may put such a tracker in every of its vehicles, thus allowing the staff to know if a vehicle is on time or late, or is doing its assigned route. The same applies for armored trucks transporting valuable goods, as it allows to pinpoint the exact site of a possible robbery.
• Stolen vehicle searching. Owners of expensive cars can put a tracker in it, and "activate" them in case of theft. "Activate" means that a command is issued to the tracker, via SMS or otherwise, and it will start acting as a fleet control device, allowing the user to know where the thieves are.
• Animal control. When put on a wildlife animal (e.g. in a collar), it allows sciencists to study its activities and migration patterns. Vaginal implant transmitters are used to mark the location where pregnant females give birth. ^[1] Animal tracking collars may also be put on domestic animals, to locate them in case they get lost.
• Race control. In some sports, such as gliding, participants are required to have a tracker with them. This allows, among other applications, for race officials to know if the participants are cheating taking unexpected shortcuts or how far apart they are. This use has been featured in the movie "Rat Race", where some millionaires see the position of the racers in a wall map.
• Espionage/surveillance. When put on a person, or on his personal vehicle, it allows the person monitoring the tracking to know his/her habits. This application is used by private investigators, and also by some parents to track their children.

See also: Automatic Vehicle Location Delivery is the process of transporting goods. ... Taxicab, short forms taxi or cab, is a type of public transport for a single passenger, or small group of passengers, typically for a non-shared ride. ... Polish armored car Ursus which saw combat during the Polish-German War of 1939. ... mtDNA-based chart of large human migrations. ... A modern glider crossing the finish line of a competition at high speed. ... Look up rat race in Wiktionary, the free dictionary. ... A private investigator, private detective, PI, or private eye, is a person who undertakes investigations, usually for a private citizen or some other entity not involved with a government or police organization. ... Automatic vehicle location is a means for determining the location of a vehicle and transmitting this information to a point where it can be used. ...

Data pullers

Contrary to a data pusher, that sends the position of the device 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. It has been suggested that this article or section be merged with Push media. ... In computing, pull technology is a network communication where the initial request for data originates from the client, and then is responded to by the server. ... Gpsd is a daemon that receives data from GPS receiver, and provides the data back to multiple applications such as Kismet. ...

Potential abuse of GPS trackers

In the US, the use of GPS trackers by police requires a search warrant, but use by a private citizen does not, as the Fourth Amendment does not limit the actions of private citizens. These devices can also raise concerns about personal privacy. Over time, the information collected could reveal a typical pattern of movements. A search warrant is a written warrant issued by judge or magistrate which authorizes the police to conduct a search of a person or location for evidence of a criminal offense, and seize the evidence. ... The Bill of Rights in the National Archives. ... Privacy has no definite boundaries and it has different meanings for different people. ...

Countermeasures against GPS trackers

The consumer electronics market was quick to offer remedies (radar detectors) to radar guns; a similar market may exist for devices to counter satellite tracking devices. Radio jamming of the relevant GPS or cell phone frequencies would be an option, as would a device which could detect the RF emissions of the GPS receiver circuitry. Though jamming of GPS signals could create a safety hazard to vehicles or aircraft within line of sight of the jammer and any deliberate radio interference is likely to be illegal in most western countries. An early radar detector A radar detector is an electronic device used by motorists to determine if their speed is being monitored. ... U.S. Army soldier uses a radar gun to catch speeding violators at Tallil Air Base, Iraq. ... Radio jamming is the (usually deliberate) transmission of radio signals that disrupt communications by decreasing the signal to noise ratio. ...

Besides this, jamming the transmission frequency of an industrial grade GPS transmitter would only work temporarily because most of them use a "store and forward" procedure to store up points that were not received and transmit them again later. This capability is built-in so tracked vehicles don't lose data when they are out of cellular range temporarily. Jamming the actual GPS frequency, however, would result in the GPS transmitter simply thinking it had lost sight of the satellites.

Notes

See also

• Automatic Position Reporting System
• Electronic tagging
• GPS Wildlife Tracking
• Gps2sms - Tracking of persons, devices or vessels by SMS
• Intelligent transportation system
• Surveillance
• Telematics
• Vehicle Infrastructure Integration
• Vehicle Tracking

Automatic Packet Reporting System (APRS) is an amateur radio based system for digital communications, most commonly used to automatically report the position (GPS coordinates) of a person or object, or weather data at a remote location. ... Electronic tagging is a form of non-surreptitious surveillance consisting of an electronic device attached to a person or vehicle, especially certain criminals, allowing their whereabouts to be monitored. ... GPS Wildlife Tracking involves the use of the Global Positioning System to determine the precise location of wild animals to which it is attached and to record their position at regular intervals. ... This article does not cite any references or sources. ... Surveillance cameras An helicopter flying over Lille, France, watching for possible rioting after the 2007 presidential election Surveillance is the monitoring of behavior. ... The term telematics is used in a number of ways: The integrated use of telecommunications and informatics, also known as ICT (Information and Communications Technology). ... Vehicle Infrastructure Integration (VII) is the ongoing development of technology which directly links vehicles with the infrastructure. ... Current vehicle tracking systems have their roots in the shipping industry. ...

External Links

• GPS Car Tracking and Navigation