| Everyone can benefit from the technology of a | | | | information on their own orbital systems. |
| GPS system. Either in your vehicle or out in the | | | | It's not necessary for the user to be equipped |
| open while camping, GPS will help you with | | | | with the precise clock, however a good short |
| valuable information. | | | | term clock may be required in order to receive |
| When you get lost who would rather go dig a | | | | the satellite transmissions best used in determining |
| hole and bury yourself in it than ask someone for | | | | the exact location on Earth. Different satellites |
| directions? If this is you, a (Global Positioning | | | | employ various sequencing modes, allowing the |
| System) GPS, is the answer to your prayers. | | | | transmission of messages to be received by the |
| GPS is an operational navigational system that | | | | user from satellites using similar frequencies. |
| utilizes navigational satellites that orbit the Earth. In | | | | The primary GPS system was created to provide |
| other words, it tracks a persons location or | | | | control over the military forces in the United |
| provides directions, all by using an existing satellite | | | | States. This allowed for improved command |
| system. GPS units also have the ability of | | | | capability, as well as the targeting and manipulation |
| providing real time reference on earth, or within | | | | of missiles, smart bombs and other forms of |
| its orbit. | | | | ammunition. The satellites are also able to detect |
| The satellite navigation system was first invented | | | | nuclear detonators. |
| and used by the USA's Department of the | | | | Civilian users can also access the GPS system |
| Defense. Later, the system was adopted for use | | | | through their GPS receivers and GPS system |
| by foreign countries including Europe (Galileo) and | | | | software. Many cities in highly urbanized countries |
| Russia (GLONASS). Today in the United States, | | | | have improved the lives of their citizens where |
| any US citizen may use the navigational system, | | | | access is available to the free worldwide GPS |
| absolutely free. | | | | Standard Positioning Service. The transportation |
| The satellite navigational system is primarily | | | | sector has greatly benefited from the system, as |
| divided into three segments: | | | | many planes, ships and cars employ GPS systems |
| A- Space: As the name suggests, the space | | | | for navigation. Hikers, glider pilots, mine truck |
| segment works from outer space. It operates | | | | drivers and everyday travelers enjoy access to |
| through a GPS satellite constellation, located in an | | | | the GPS system through low cost GPS receivers, |
| Intermediate Circular Orbit. | | | | ranging in price from $100 to $200. GPS receivers |
| B-Control: The control segment of a satellite | | | | that are more precise are widely used by land |
| navigational system is comprised entirely of | | | | surveyors for measuring land surface area, |
| control stations that are located on earth. These | | | | locating boundaries and surveying markers. |
| terrestrial control stations are scattered at | | | | Time code generators also depend on the GPS |
| locations around the world. These control the flight | | | | system to acquire accurate time for precisely |
| paths of the various GPS satellites, and | | | | recording events in real time. Developers are also |
| synchronize the atomic clocks in the satellite. | | | | working on specially created GPS systems that |
| Ground stations also monitor the uploading of data | | | | will help visually impaired individuals. |
| through the satellite transmissions. | | | | Another, more trendy use of GPS receivers is |
| C- User: The satellite navigational system is mainly | | | | the widely popular hobby of Geocaching. Children |
| made up of civilian and military GPS receivers. | | | | and adults use hand held GPS receivers to |
| GPS is technically comprised of 24 satellites, the | | | | navigate designated sites and locate hidden |
| minimum number of satellites in a constellation. | | | | objects. There are numerous Geocaches hidden all |
| These satellites orbit around six orbital planes, | | | | over the world, with coordinates available on |
| twice in every twenty-four hour period. Each | | | | Geocaching websites. |
| satellite carries an atomic clock, which continuously | | | | The GPS system has brought both enthusiasm |
| transmits precise time to the ground | | | | and easiness to the lives of people all over the |
| observatories located in the Earth. In addition, the | | | | globe. Despite the complexity of the system, |
| satellites send electronic messages to the Earth. | | | | anyone with a GPS receiver can use the service, |
| These messages may include data on precise | | | | free of charge. So from now on you will have no |
| time based upon the on-board satellite clocks, or | | | | excuse for getting lost. |