Garmin GPSMAP 3210 Owner's Manual - Page 111

Satellite Information Center dot - 90° 90° above the horizon Inner ring- 45° above the horizon Outer ring the horizon 45° Satellite Sky View Satellite Location The location of each available satellite is shown over two location rings on the Satellite Information Page. The outer ring represents the horizon, the inner ring represents 45° above the horizon, and the center dot represents a point directly overhead. When the unit is using a satellite for navigation, the satellite number is highlighted on the location rings. The unit can be set to display satellite location with North or your current track at the top of the display. Satellite Strength Indicator Bars The Satellite Strength Indicator Bars show the strength of the signal being received and the status of the signal. The bars are either shaded or filled. A hollow gray bar means the unit is in the process of storing orbital data it is receiving from the satellite signal. When the bar turns solid green, the unit is using the satellite signal for navigation. A "D" in or above the bar means differential corrections (WAAS or DGPS) are being applied to that satellite. Date, Time, and Current Location The unit gets date and time information from the satellite's on-board atomic clock. When the unit has achieved a 2D or 3D GPS location, the current location is shown in the location format you have selected GPSMAP 3206/3210 Owner's Manual Appendix > Satellite Information and What is WAAS/EGNOS? What is WAAS/EGNOS? The Wide Area Augmentation System (WAAS) is an FAA-funded service to improve the overall integrity of the GPS signal for users in North America. In Europe, WAAS is referred to as EGNOS. The system is made up of satellites and 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 data correction message. According to the FAA's Web site, testing of WAAS in September 2002 confirmed an accuracy performance of 1-2 meters horizontal and 2-3 meters vertical throughout the majority of the continental United States and portions of Alaska. WAAS is just one service provider that adheres to the Minimum Operational Performance Standard (MOPS) for global Satellite Based Augmentation Systems (SBAS). Eventually there will be several services of worldwide geostationary communication satellites that broadcast integrity information and differential correction data as transmitted by ground reference stations. All SBAS systems use the same receiver frequency; therefore any operational SBAS system should be capable of providing your GPS unit with increased accuracy at any location in the world. Currently, enabling WAAS on your GPSMAP 3206/3210 in regions that are not supported by ground stations may not improve accuracy, even when receiving signals from an SBAS satellite. In fact, it can degrade the accuracy to less than that provided by GPS satellites alone. For this reason, when you enable WAAS on your Garmin GPS receiver, the receiver automatically uses the method that achieves the best accuracy. For more information, go to gps.faa.gov. 103 Appendix