GPS Tracking Technology
GPS is mantained by the United States and can be used by all the people who have GPS reciever. If there are no obstructions in line of sight it provides time and location information in all conditions. Being very useful its uses are getting more numerous and spread each and every day.
The Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites. It is maintained by the United States government and is freely accessible to anyone with a GPS receiver.
The GPS program provides critical capabilities to military, civil and commercial users around the world. In addition, GPS is the backbone for modernizing the global air traffic system. 
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 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 (e,g, Telematics 2.0). 
Increasing commercial use of the Global Positioning System will soon make it possible to locate anything, anywhere, anytime. The Global Positioning System can provide extremely accurate location information for mobile objects and people which is far superior to earlier tracking techniques. The challenge today is integrating the necessary components into older systems and improving GPS accuracy in areas with numerous obstructions. As more devices become GPS enabled, accuracy will increase and the system’s scale and global reach will benefit everyone. Wireless technology promises to be a key element in any long-term solution. 
Problems in existing manual methods of identifying, tracking and locating highly customized prefabricated components result in late deliveries, double-handling and misplacement of components, and incorrect installations that lead to schedule delays and increased labor costs. To eliminate these deficiencies, an automated system using radio frequency identification technology combined with GPStechnology, requiring minimal worker input, is proposed. The requirements and approaches needed to utilize the system for locating precast concrete components with minimal worker input in the storage yard of a manufacturing plant were developed. Based on the requirements identified and approaches formalized, a prototype system was developed, assembled and tested in the field at a precast storage yard. The prototype system succeeded in automatically identifying pieces that were relocated, demonstrating feasibility of the approach. 
GPS tracking technology has proven to be extremely useful but it also invades people’s privacy sometimes. A line has to be drawn between its good sides and the negative ones in order not only to improve its potentials but also the way it is used.
 ”GPS: location-tracking technology” by: Bajaj, R.
 ”Tracking and locating components in a precast storage yard utilizing radio frequency identification technology and GPS” by: Esin Ergena, Burcu Akincib, Rafael Sacks
 ”Real-time tracking management system using GPS, GPRS and Google earth” by: Chadil, N.