A Brief History of…Satellite Systems
When we think of GPS’ we think of a single and all-encompassing global positioning system – but this isn’t the case! Did you a ‘GPS’ is actually just one of four global positioning systems used today? The four global positioning systems include:
- GPS –From the United States and consists of 24 satellites included in the satellite system.
- Glonass – From Russia (with love) and consists of 24 satellites, orbiting 19,000 km above earth.
- Compass – From China and consists of 10 satellites (soon to be 35 by the year 2020.
- Galileo – From European Union countries and consists of 30 satellites, orbiting 23,000 km above earth.
‘But how did this come about?’ You may ask? – Well check out this global positioning satellite timeline:
1957 – The Soviet Union launched ‘Sputnik’, the 1st satellite
1959 – The United States launched ‘Transit’, which was implemented as a navigation satellite to help with chips and airplane’s navigation systems.
1978 – The first GPS satellite launched by the United States. Shortly after this, to keep airlines from straying into foreign territories and foreign countries, the U.S. allowed major airlines to access their GPS satellites.
1989 – The 1st modern GPS was launched by the United States.
1995 – The full 24-satellite constellation for the American GPS was launched.
2000 – President Clinton instructed the Department of Defense to disable the GPS’ selective availability mode on the satellites. Selective availability was a strategy for creating an intentional error into the GPS system, with the military being the group who knew what and where the error was. This strategy therefore allowed the U.S. military to better pinpoint enemies who had intentionally built errors into their system. However, the U.S. realized that the civilian use for the GPS was growing at a rapid rate, and removed this ability to add or scramble an intentional error into the GPS signal.
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