| It might seem magical but there is only science | | | | to helping us know where we are at any given |
| and technology involved. It is called a global | | | | time. That is, if we have a global positioning |
| positioning system or GPS. I was first introduced | | | | system handy. |
| to them while a soldier. At that time the | | | | The satellites know where there are all the time. |
| technology was new and often unreliable. It was | | | | They are constantly sending out radio beams that |
| more an interesting toy but to find out where I | | | | are picked up by ground stations. Much like radar |
| was I used topographical map. But that was then | | | | or sonar the location is determined by the time it |
| and this is now. | | | | takes to reach the station. |
| You might have seen advertisements. You might | | | | Since it is known that people are counting on |
| have had someone show you what it does. You | | | | accuracy the systems use atomic clocks to |
| might have a friend or acquaintance who is often | | | | ensure to time is correct. This timing system |
| bragging about their GPS and how do they do it. | | | | combined with built-in technology designed to |
| The purpose of the GPS is to tell you where in | | | | correct errors results in a reliable location read-out. |
| the world you are. Though not mandatory to able | | | | A system is formed between the satellites, the |
| to use it would be nice to know how it works. | | | | ground stations and your device. Together a |
| You have probably seen a globe in your | | | | highly complex triangulation computation is |
| classroom when in school and many other places. | | | | created. The results are that you are provided |
| You might have noticed the horizontal and | | | | with your location with a high degree of accuracy. |
| verticals lines on it. These are latitude and | | | | Your GPS listens for a signal from 4 satellites and |
| longitude measured in degrees, minutes and | | | | provides you with your location. |
| seconds | | | | This is a simplified overview of how the global |
| The grid or matrix created by the horizontal and | | | | positioning system works. It is more complex this |
| vertical lines is the foundation for the global | | | | but it is not required to fully understand the |
| positioning system. | | | | workings to be able to benefit from it. As you |
| High in the sky there are 24 GPS satellites | | | | can see it is not magic but you must agree it is |
| orbiting, courtesy of the U.S. Air Force. They are | | | | magical. |
| packed full of electronics and software dedicated | | | | |