GPS

The Global Positioning System or GPS or Navstar is a network of satellites controlled by the United States military that the military and civilians use for navigation purposes. There are 24 satellites in all that orbit the Earth every 12 hours sending a synchronized signal from each individual satellite. When four of these satellites are synced with a receiver, they are able to calculate where the user is to within a few feet of them.

Utility

The network of satellites sends positioning information to receivers in people's phones and Sat Navs. It was discovered because the U.S. military wanted to increase the accuracy of the U.S. Airforce's bombers. The United States, because it controls the GPS satellites has at numerous times denied or degraded the service such as when they denied service to the Indian military during the Kargil War.

Inventor(s)

Roger L. Easton, Ivan Getting, and Bradford Parkinson are credited with the invention of the Global Positioning System.

Access & Availability

The DNSS would evolve into what modern day humans know as GPS with President Ronald Reagan making GPS available for civilian use and President Bill Clinton signed a directive to make GPS as accurate for civilians as it was for the military. Since then GPS has become more accurate and reliable with most Americans relying on GPS to get around.

Complexity

The Global Positioning System is a network of satellites that transmit data to any GPS receiver anywhere on Earth. GPS works without user input and works without the need of telephone or internet reception. Telephone and internet reception can, however, be used to make the positioning information far more accurate.

Discovery

During Labor Day in 1973, a group of twelve military officials met at the Pentagon to discuss the creation of a Defense Navigation Satellite System.