Man’s entry into the space age also marked the beginning of the early days of the Global Positioning System, or GPS. Developing such a system that would give a clear military advantage to the United States in the Cold War arms race required billions of dollars in investment, something that proved to be easily funded at the time by US Congress. With 5 satellites being able to track an object every hour, the first experimental GPS system was developed by the US Navy called Transit.
GPS takes its name from the Navstar-GPS system, but it was originally known as the Defence Navigation Satellite System during the 1970s and then subsequently called Navstar. In 1983 President Reagan made the system available for non-military use after the infamous incident where a Korean civilian aircraft was shot down after straying into Soviet air space, killing all 269 passengers on board; Reagan argued that such accidental straying must not be allowed to happen again. In 2000 President Clinton switched off what was known as Selective Availability, an intentional margin of error of about 20m introduced into the early systems so as to make them inaccurate due to security reasons, with the best signals reserved only for military use.
The system currently uses 24 satellites in its network, circling the earth every 12 hours, 12,000 miles high. Most devices only require 4 or more satellites to get their ‘fixes’ and determine their height, location and speed by calculating the difference between these satellites and the atomic clocks they carry on board.
The current GPS system is under continuous development and is extremely widespread, with some estimates putting its worldwide market value at $75 billion by 2013. Belonging to the US Government, it can be found in many sectors thanks to its improved technology and cheaper costs. Used by millions of people, it has many applications from keeping track of animals and children as well as personal belongings and property including cars, which make them easier to find if they are stolen. And as with most things modern, they have gotten much smaller and can now be found in mobile phones, dog collars and even on the wrists of many sports professionals and enthusiasts in the form of GPS Sport Tracking devices. Commercial fishing, geologists studying earthquakes, courier companies, hikers… an ever-increasing array of businesses and people now depend on GPS for their day-to-day activities.