GPS

=GPS=

==

Description:
GPS stands for Global Positioning System. The system uses a group of satellites positioned all around the earth, creating a sort of field for the signal to bounce off of.

History:
The system was developed by American Department of Defense and first tested in 1978 with 10 satellites. After an accidentally trespassing (due to navigation errors) civilian airliner was shot down by Soviet interceptors in 1983, then-president Ronald Reagan announced that the system would be available for civilian use once it was completed. Full operational capacity was declared in 1995. The system was declared a national asset in 1996 by then-President Bill Clinton.

Function:
The GPS in use by civilians are known to have three basic components; absolute location, relative movement and time transfer. It is primarily used for navigation aid (hence it's usage in vehicles). The system is used in devices such as the iPhone or iPod touch (notably in apps such as Maps, Google Earth and Urbanspoon). External GPS receivers can be purchased for some devices, such as a PlayStation Portable (pictured below).