| The technology behind GPS systems can be | | | | of whether the satellite is working to its |
| complicated. However, a little research into | | | | greatest potential or not. |
| what the various systems are and how they | | | | |
| work can make choosing the right GPS system | | | | There are around 25 different ground |
| an easier decision. If you have looked into | | | | stations, which WAAS uses as reference in the |
| purchasing a GPS or owned a GPS system before | | | | United States alone. The GPS satellite data |
| then you probably have seen the term WAAS | | | | is communicated to these ground stations so |
| either on packaging or in ads for GPS | | | | the information can be monitored. Then the |
| systems. | | | | information is compiled and sent to two |
| | | | master stations (one on the east coast and |
| WAAS stands for Wide Area Augmentation | | | | one of the west coast), which correct any |
| System. WAAS is an intricate GPS technology, | | | | errors in the GPS satellite information. |
| which was developed to provide locations that | | | | |
| are more accurate. This is done through GPS | | | | Corrections are made based on the orbit of |
| signal corrections attained through a network | | | | the satellite, clock drift, and delays in the |
| of ground stations and satellites. The | | | | signal caused by the ionosphere and |
| stations and the satellites work together to | | | | atmosphere of the Earth. After the |
| create plots on maps so GPS systems can | | | | corrections are made, the master station |
| easily make this information available to the | | | | transmits this information to a geostationary |
| consumers that use these products. | | | | satellite (one of two), which are located in |
| | | | a stationary position over the equator. Since |
| WAAS is still being developed through the | | | | the information is GPS compatible (the signal |
| joint efforts of the FAA (Federal Aviation | | | | structure is the same) a GPS receiver with |
| Administration) and the DOT (Department of | | | | WAAS is able to read the signal from the |
| Transportation). The reason the DOT and the | | | | satellite. |
| FAA are developing WAAS is actually to make | | | | |
| flight locations more accurate. WAAS works | | | | At the present time, only people in North |
| together with GPS because GPS does not | | | | America can use WAAS technology. GPS can be |
| currently meet navigational requirements of | | | | used in South America. However, WAAS will not |
| the FAA on its own. | | | | work to correct accuracy errors. This is |
| | | | because WAAS enabled GPS receivers cannot |
| At this time, WAAS is five times more | | | | receive signals due to the fact that South |
| accurate than the average GPS system | | | | America has no ground stations. WAAS |
| technology. In fact, a GPS receiver with WAAS | | | | technology is constantly being tweaked and |
| capabilities can maintain an accuracy of | | | | improved though, so in time it could become |
| three meters or less over 90% of the time. Of | | | | available across the world. |
| course, the best feature of WAAS is that it | | | | |
| is built in to certain GPS systems. This | | | | For now, it is best to use WAAS enabled GPS |
| means there are no additional fees and you do | | | | systems in open land or at sea. Since the |
| not have to order any additional receivers or | | | | stationary satellites are at the equator, it |
| other equipment for WAAS to work correctly. | | | | can be hard to receive the transmission if |
| Additionally, depending on the type of GPS | | | | you are not close to the equator or if the |
| device you own, you may be able to upgrade | | | | signal is being blocked by mountains, trees, |
| your GPS system to start using WAAS | | | | or other natural and man made objects that |
| capabilities if it does not do so already. | | | | get in the way. |
| | | | |
| GPS alone faces problems such as ionospheric | | | | While WAAS technology is not perfect, it is |
| disturbances, precision timing, and orbit | | | | much better than what is currently available. |
| errors for the satellites used. However, when | | | | As the system improves, the accuracy will |
| used together with WAAS, these three main | | | | improve, making WAAS one of the leading |
| problems, as well as smaller errors in the | | | | technology systems for GPS receivers. You can |
| GPS system are corrected. WAAS is also | | | | find out if a GPS system is WAAS compatible |
| capable of providing information on the GPS | | | | by looking on its package or searching |
| satellite itself so there is never a question | | | | online. |