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Great for cruising unfamiliar territory or exploring trails Product Information Garmin's eTrex is one of the smallest GPS units you'll find with built-in coastline, road and highway detail. eTrex Legend is right at home on your dash or in your hand as you hike the trials or search for the nearest restaurant. With the eTrex Legend, Garmin has loaded a full basemap of North and South America into one small unit. The Legend is also designed to provide precise GPS positioning using correction data obtained from the Wide Area Augmentation System (WAAS). This product will provide position accuracy to less than three meters when receiving WAAS corrections.
You've heard the term WAAS, seen it on packaging and ads for Garmin products, and maybe even know it stands for Wide Area Augmentation System. Okay, so what the heck is it? Basically, it's a system of satellites and ground stations that provide GPS signal corrections, giving you even better position accuracy. How much better? Try an average of up to five times better. A WAAS-capable receiver can give you a position accuracy of better than three meters 95 percent of the time. And you don't have to purchase additional receiving equipment or pay service fees to utilize WAAS. The basemap contains lakes, rivers, cities, interstates, national and state highways, railroads and coastlines. The eTrex Legend is also equipped with additional memory totaling eight megabytes. The added memory allows the eTrex Legend to accept downloaded map data from Garmin's entire line of MapSource CD-ROMs, including U.S. Recreational Lakes with Fishing Hot Spots. The eTrex Legend comes in a brightly-colored translucent blue case that really makes the unit stand out. New to the product design, Garmin will include marine aids to navigation in addition to the basemap. These navigational aids will be pre-loaded into each unit from the factory.
Unique Advantages The origins of WAAS: The Federal Aviation Administration (FAA) and the Department of Transportation (DOT) are developing the WAAS program for use in precision flight approaches. Currently, GPS alone does not meet the FAA's navigation requirements for accuracy, integrity, and availability. WAAS corrects for GPS signal errors caused by ionospheric disturbances, timing, and satellite orbit errors, and it provides vital integrity information regarding the health of each GPS satellite.
How it Works: WAAS consists of approximately 25 ground reference stations positioned across the United States that monitor GPS satellite data. Two master stations, located on either coast, collect data from the reference stations and create a GPS correction message. This correction accounts for GPS satellite orbit and clock drift plus signal delays caused by the atmosphere and ionosphere. The corrected differential message is then broadcast through one of two geostationary satellites, or satellites with a fixed position over the equator. The information is compatible with the basic GPS signal structure, which means any WAAS-enabled GPS receiver can read the signal.
Who benefits from WAAS? Currently, WAAS satellite coverage is only available in North America. There are no ground reference stations in South America, so even though GPS users there can receive WAAS, the signal has not been corrected and thus would not improve the accuracy of their unit. For some users in the U.S., the position of the satellites over the equator makes it difficult to receive the signals when trees or mountains obstruct the view of the horizon. WAAS signal reception is ideal for open land and marine applications. WAAS provides extended coverage both inland and offshore compared to the land-based DGPS (differential GPS) system. Another benefit of WAAS is that it does not require additional receiving equipment, while DGPS does.
Other governments are developing similar satellite-based differential systems. In Asia, it's the Japanese Multi-Functional Satellite Augmentation System (MSAS), while Europe has the Euro Geostationary Navigation Overlay Service (EGNOS). Eventually, GPS users around the world will have access to precise position data using these and other compatible systems.
KeyFeatures Include
Product Specification
Display: 2.1"H x 1.1"W (5.4 x 2.7 cm) high-contrast LCD with bright backlighting
Case: Waterproof to IEC 529 IPX7 standards
Temperature range: 5°F to 158°F (-15°C to 70°C)
Internal Memory: 8 MB
Minimum Requirements
Requires MapSource data to look up services and points of interest
