What is GPS?

GPS (Global positioning system) is a navigation system made up of a network of 24 satellites orbiting at 11,000 nautical miles above the Earth. The system allows for continuous transmission of code information, which makes it possible to identify precise locations on Earth by measuring distance from the satellites. It is the only system today that is able to show an exact position on Earth anytime, in any weather condition, anywhere. Signals transmitted by the satellites can be detected by anyone with a GPS receiver. GPS is one the most revolutionary inventions in history, and new uses are still being discovered daily. GPS combined with wireless communication, the Internet, sensors, mobile computing and other cutting edge technologies are pushing human power and wireless communication to a higher level.

How does GPS work?

GPS measures the distance between the receiver and the satellites to identify location. Each satellite generates signals that allow a receiver to estimate the satellite location and distance between them. The receiver then uses these measurements to calculate location. Essentially, the receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. With a few distance measurements from a few satellites, the receiver can determine the user's exact position and display it on the unit's electronic map. A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user's 3D position (latitude, longitude and altitude). Once the user's position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, and more.

GPS in our daily life

GPS is rapidly changing the way people navigate and not to mention how it has enhanced our life. GPS has a variety of applications on land, at sea and in the air. Basically, GPS is usable everywhere except where it's impossible to receive the signal such as inside most building and underwater. GPS-equipped fleet vehicles, public transportation systems, delivery trucks, and courier services use receivers to monitor their locations at all times. GPS is also helping to save lives, many police, fire, and emergency medical service units are using GPS receivers to determine the police car, fire truck, or ambulance nearest to an emergency, enabling the quickest possible response in life-or-death situations.

The system has been used in aircraft and ships with vehicle tracking being one of the fastest-growing GPS applications. Some basic systems are in place and provide emergency roadside assistance at the push of a button (by transmitting your current position to a dispatch center). More sophisticated systems that show your positions on a street map are also available. Currently these systems allow a driver to keep track of where he is and suggest the best route to follow to reach a designated location.
The future of GPS is as unlimited as our imagination. New applications will continue to be created as the technology evolves. The GPS satellites, the handmade stars in the sky, will be guiding us well into the 21st century.