GPS

It is a global navigation satellite to determine the world position of an object, a person or a vehicle with an accuracy up to centimeters, although usually are a few meters of accuracy. The system was developed, installed and currently operated by the Department of Defense of the United States.

The GPS works through a network of 24 satellites in orbit above the planet earth, 20,200 km, with synchronized paths to cover the entire surface of the Earth.

In 1957, the Soviet Union launched the Sputnik satellite into space I, which was monitored by observing the Doppler shift of the signal transmitted. Due to this fact, they began to believe that, similarly, the position of an observer may be established by studying the Doppler frequency of a signal transmitted by a satellite whose orbit was accurately determined.

The former Soviet Union built a similar system called GLONASS, now managed by the Russian Federation.

Currently the European Union is developing its own satellite positioning system called Galileo.

In turn, the Republic of China is implementing its own navigation system, called Beidou, which provide that has between 12 and 14 satellites between 2011 and 2015. 2020, and must have fully operational with 30 satellites. At the moment (April 2011), and have 8 in orbit.

I think that is the most great invention because thanks to it we can locate and know where we are, we also know the distance at which we arrive somewhere and we want to know which way we would go, it's like a smart compass. to people who are guided by GPS compasses gives them more easily when guided, and for people who have difficulty using these devices, the GPs shows no such difficulty and they can also serve those people.