| The name WAAS as it applies to GPS, just what | | | | meters) |
| is it, and precisely what does it mean when it | | | | Differential GPS (DGPS) location accuracy. 9 - 15 |
| comes to you? | | | | feet (3-5 meters). (The differential GPS needed |
| WAAS is an acronym for Wide Area | | | | supplemental equipment) |
| Augmentation System. | | | | Today's normal WAAS location accuracy. 9 feet |
| One may have noticed it in advertisements and | | | | or even less (Less then 3 meters). |
| boxes for Garmin hand held and some other GPS | | | | You don't have to buy any additional devices or |
| units. | | | | spend any extra charges to utilize it. This is |
| The question is... what is it? | | | | included in each and every Garmin hand held |
| WAAS is a system of satellites and ground | | | | WAAS enabled GPS. |
| stations that provide GPS signal modifications, | | | | Precisely what is WAAS? |
| providing you actually greater position accuracy. | | | | The actual WAAS structure is 20 or more ground |
| How much better? | | | | reference stations positioned in the United States |
| Several experts say anywhere from 4 to 5 times | | | | that monitor GPS satellite information. There is |
| greater. A GPS together with WAAS capable | | | | one master station at each coast which collect |
| receiver can easily give an individual a position | | | | this information from the satellites and adjust the |
| accuracy of better than three meters, that's less | | | | information to make a correction regarding |
| than 9 feet, 95 percent of the time. | | | | satellite orbit, as well as weather in addition to |
| Let's look at original system functions prior to | | | | stellar conditions. This data as well as correction |
| WAAS GPS devices. | | | | will be routed through two stationary satellites to |
| The original GPS navigation program was initially | | | | your Garmin hand held GPS making location |
| subject to accuracy and reliability degradation | | | | accuracy and reliability inside of 3 meters for 95% |
| under the government-imposed Selective | | | | of the time. |
| Availability (SA)* program. | | | | Who gains from WAAS? |
| Accuracy and reliability within 300 feet (100 | | | | Virtually any WAAS enabled GPS user within |
| meters) | | | | North America. This particular system is not in use |
| *(This was the system which actively sent | | | | on other continents, but numerous countries are |
| incorrect location data a number of times. When | | | | rushing to developing comparable systems. |
| you believed that you were on your fishing place | | | | Does is work everywhere? |
| in the Great lakes, you might be as far as 300 | | | | Whenever structures, trees or mountains |
| feet off where your system says you are. That | | | | obstruct the view of the horizon this could result |
| is about 3/4 of a typical city block. The software | | | | in weak signal reception coming from the satellites |
| was set up in order to dis-wade use associated | | | | positioned over the equator. The application works |
| with GPS unit systems for illegal applications. This | | | | most effective on open water and unobstructed |
| specific SA system was ceased under the Clinton | | | | land areas, but this particular process is |
| administration, however can easily be started | | | | continuously updating with new technology |
| again in the occurrence of some sort of | | | | through Garmin hand held GPS systems. The |
| nationwide emergency) | | | | capability to receive the WAAS correction info is |
| GPS location accuracy and reliability prior to | | | | definitely improving together with each and every |
| WAAS, and SA was not activated. 45 feet (15 | | | | new model introduced. |