Here are some interesting gps facts – DID YOU KNOW?
1. There are a total of 31 satellites, including 2 reserve satellites, out of which at least 24 GPS satellites orbiting the earth. This means that each GPS satellite orbits the earth in every 12 hours.
3. When Soviet Union launched Sputnik in 1957, two American physicists started monitoring the satellite’s transmissions. They soon realised that they could identify the satellite in its orbit using Doppler Effect . This would later become the key principle used in GPS system. The change in frequency of signals from the GPS satellites helps in identifying locations.
5. Before GPS came into existence, navigation system of Navy was being used. Their need of a faster navigation system for high speed air force operations forced them to think whether navigation using satellites is possible.
6. In the beginning, GPS was called Navstar. The first Navstar satellite was launched in 1978. Out of the ten satellites launched, only nine made it to the orbit. The first fully developed GPS satellite was launched in 1989.
7. GPS was open to the public following a disaster. In 1983, Korean Airlines Flight 007 was shot down by Soviet Union killing 269 passengers on board as the flight entered the prohibited Soviet airspace. This incident prompted President Ronald Reagan to provide public access to the United States military satellite navigation system DNSS, which is known as GPS at present.
8. Though availability of GPS was made public, high quality GPS signals were confined to military use until recently. However, on May 1, 2000, this practice was taken off. At present, the GPS for civilian purposes is more accurate.
11. If you thought GPS was all about navigation, you were wrong. It can also be used to determine the accurate time. Each GPS satellites consist of atomic clocks and time signals that the GPS receiving device can use to obtain the correct time. These signals are used to set the time in our mobile phones.
13. Do you know who invented the GPS navigation system? Bradford Parkinson of the Applied Physics Laboratory, Ivan A. Getting of The Aerospace Corporation, and Roger L. Easton of the Naval Research Laboratory