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GPS, the full name is Global Positioning System, is a Satellite navigation system that allows land, air and sea users to determine their exact location. With 24 satellites that GPS device connected make GPS device can determine every locations in the world and the bad weather doesn’t affect the quality of signal. GPS need 4 satellites to calculate the position by measurements 4 variables –x,y,z and t and return to user a friendly data like latitude and longitude or graphic data such as a map. These will make positioning accuracy around 10-100 m. Some of GPS can also calculate your speed and your direction when you are moving so you can estimate times of arrival to destination.
In 1972, The US Air Force start to develop and testing the GPS for use in military purpose but now it common uses for home users. There are a lot of GPS devices released from many manufacturers and because decreasing of price of GPS devices make them very popular in the market now so many products starting included GPS function on their product such as PDA GPS, Cell Phone GPS, Car with GPS, etc.
Do I need GPS?
Try to imagine that you are going to visit your friend at New York City. You know the address, road but you never go there before. Ok if you have a map it can help you but for a really big city it should make you headache for finding road, which way to go next? That the reason to use GPS. GPS can help you. You can see your location in the map and you can see which way you moving to. You can zoon in and zoon out to search your destination. So just look at screen and find your route then go ahead, you never lost again. |
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