| Before the arrival of the General Positioning | | | | in order to increase the correctness of GPS |
| System (GPS) technology, having a trip was | | | | systems. Having located the satellites, the |
| certainly the most daunting experience in our life. | | | | triliteration is used to work out its distance and |
| For instance, it was perfectly acceptable to see a | | | | reduce these errors. |
| situation where someone was driving his car, | | | | Briefly speaking, GPS systems are used for |
| another one was looking at the map to find the | | | | several purposes mainly as guiding aid. The user |
| right direction, quite funny! Nowadays, this | | | | simply needs to input his final destination and the |
| situation is obsolete and ridiculous for GPS | | | | GPS receiver will do the rest of the job. GPS |
| systems have drastically changed the way we | | | | systems can also be used for tracking purposed |
| used to deal with route finding during a trip. | | | | as it is noticed in the automobile industry. |
| Indeed by just installing a GPS device in your car, | | | | The GPS technology is also used for many other |
| you can accurately and safely get the right | | | | purposes. For instance, in the automobile industry, |
| direction. | | | | GPS systems are used to deter car thieves. |
| Usually when someone mentions GPS, he is | | | | Private investigators are also making use of the |
| referring to the GPS receiver even if the GPS | | | | GPS technology in order to monitor a cheating |
| architecture is actually more complex than this | | | | wife. The GPS technology is also extensively used |
| small device installed in your car. In short, GPS | | | | in the military industry as it was pioneered by the |
| systems are a cohort of 27 satellites rolling | | | | army. Some military usages include navigation, |
| around the center of the Earth. Only 24 satellites | | | | target tracking, missile and weapon guidance, |
| are fully functional while the remaining ones are | | | | search and rescue lost soldiers and |
| just used for storage purposes. The military | | | | acknowledgement and map creation. The |
| industry pioneered the technology before being | | | | possibility to keep track of a vehicle position |
| used for general purpose by the public. | | | | every time is an appealing feature of the GPS |
| Each GPS satellite powered by the Sun rotates | | | | technology. Other systems can furthermore keep |
| around the center of the Earth completes a | | | | track of a driver. This feature is of great help to |
| distance of about 12,000 miles which is equal to | | | | anxious parents who are concerned about their |
| 19,300 kilometers. The actual trajectories of | | | | children’s ability to safely drive. |
| these satellites are made so that at least four | | | | Another use of the GPS for civilian purpose is to |
| satellites are available in the space at any time. | | | | help prevent civilian GPS guidance from being used |
| The GPS receiver is responsible of finding these | | | | in an enemy's military or improvised weaponry, |
| available satellites, working out its distance to | | | | the US Government controls the export of civilian |
| these satellites and finding its position. This | | | | receivers. A US-based manufacturer cannot |
| process makes use of a mathematical model | | | | generally export a GPS receiver unless the |
| called trilateration. | | | | receiver contains limits restricting it from |
| The GPS signals are hindered by weather | | | | functioning when it is simultaneously at an altitude |
| conditions. Nowadays, there are many research | | | | above 18 kilometers and traveling at over 515 m |
| projects aiming at finding ways around this issue | | | | s. |