| GPS stands for Global Positioning System and | | | | is. If a GPS is receiving signals from three |
| was initially designed to be used by the U.S. | | | | satellites it can calculate latitude and |
| military and is operated by the U.S. Defense | | | | longitude. Altitude can be determined if the |
| Department. This system consists of 24 | | | | GPS is receiving signals from four |
| satellites, these satellites are 12,000 miles | | | | satellites. |
| above us, are constantly moving in a precise | | | | |
| orbit, have an atomic clock, and are solar | | | | GPS can be used for navigating your car |
| powered. They do have a battery backup so | | | | through traffic day-to-day or tracking a |
| they will continue to run in the event of a | | | | fleet of vehicles. Not only can a driver use |
| solar eclipse, and each satellites has a | | | | a GPS for directions the main office knows |
| small rocket booster to maintain their orbit. | | | | where that vehicle is and the speed of the |
| The first satellite was launched in 1978 and | | | | vehicle. GPS can be used while on vacation |
| it wasn't until 1994 when there were a total | | | | for activities such as hiking, camping, or |
| of 24 satellites. Each satellite has a life | | | | hunting. Is your passion fishing but get |
| expectancy of about 10 years, so new | | | | frustrated trying to find the fish? With a |
| satellites are constantly being built and | | | | fish finder which uses both GPS technology |
| launched. Each satellite weighs about 2,000 | | | | and sonar you'll know exactly where to go to |
| pounds and is approximately 17 feet in width | | | | find those fish. GPS technology is also |
| when the solar panels are extended. In the | | | | being used as a way to track your pet if he |
| 1980s the GPS became available to the public, | | | | wanders off or to safeguard a pet from being |
| and although it is still maintain by the U.S. | | | | stolen. |
| Defense Department there is no charge for its | | | | |
| usage by the public. | | | | Another use for GPS is as a child finder with |
| | | | a receiver in a child's cell phone or |
| These 24 satellites orbit the earth twice a | | | | wristwatch to ensure a child's safety. It |
| day and continuously sends the location of | | | | can be used in a teenager's car in order to |
| the satellite. A GPS system can tell how far | | | | both know where they and how fast they are |
| a satellite is away by comparing the time | | | | driving. This could also be used to keep |
| difference between the time a signal was | | | | track of someone who tends to 'roam' but is |
| transmitted and the time it was received, the | | | | not capable enough to find there way back; |
| longer it takes the signal to be received by | | | | i.e. someone with Alzheimer's disease. |
| a receiver, the farther away the satellite | | | | |