Global positioning system (GPS) tracking is the use of satellites along with a GPS device to track the location of a person or object on or near the surface of the earth. GPS tracking requires the use of four or more satellites in a medium orbit around the earth to calculate the position of a tracking device within a fairly accurate degree of proximity. A GPS tracker can take a variety of forms and serve several different functions, but the overall process used by them is mostly similar. The three basic types of GPS trackers are data pushers, data loggers, and data pullers.
GPS tracking allows a person to determine his or her own location in the event of becoming lost or disoriented while hiking or traveling. Tracking devices have been used for some time on vehicles and on other important or valuable items to help locate them in case of loss or theft. GPS tracking devices have also been used for nature research to help track the position and movements of wild animals and to determine migratory patterns for mating and birthing among such animals. Such tracking can also be used in conjunction with a device like many modern mobile phones to help track lost or abducted children as well.
A GPS tracker is required to establish position through GPS tracking of a person or object. For many people, this can be a simple device such as a phone or handheld messenger. These types of devices are typically referred to as data pushers that periodically push or send out a signal to a receiver that tracks the movements and positions of the tracker. Simpler GPS tracking devices can be data loggers that use GPS to determine position periodically over a certain period of time, then allow a user to connect the device to a computer or other hardware to access the stored positional data. Data puller devices constantly track position through GPS but only transmit positional information upon request by another system and are often used in objects that do not need consistent tracking but may require tracking if stolen or lost.
GPS tracking requires the use of four or more satellites to accurately locate a GPS tracker on the surface of the earth or flying above the surface. While only three satellites would technically be required for accurate tracking, even minor errors in data received when calculated with the speed of light to determine positioning could lead to grossly inaccurate location results. To offset this possibility as much as possible, one or more additional satellites is used to reduce the chance of erroneous data being used to calculate position.