Garmin GPSMAP 276C Owner's Manual

Also see for GPSMAP 276C: Owner's manual Owner's manual Quick reference guide Declaration of conformity Owner's manual

Contents

• Searching for WAAS—WAAS is enabled and the receiver issearching for WAAS signal.• Using WAAS—WAAS capability is enabled and the unit isreceiving WAAS corrections.• Check Beacon Wiring—the DGPS setting is enabled in theInterface sub tab on the Main Menu—Setup tab, but no DGPSdevice is detected.• No Beacon Signal—DGPS receiver is attached, but nottransmitting RTCM data to GPS.• Tuning Beacon—the receiver is tuning manually to a DGPSfrequency.• Using Differential—the unit is receiving DGPS corrections.• Scanning for Beacon—the DGPS receiver is scanning for anavailable frequency.What is WAAS?The Wide Area Augmentation System (WAAS) is an FAA-fundedproject to improve the overall integrity of the GPS signal andincrease position accuracy for users in North America.The system is made up of satellites and approximately 25 groundreference stations positioned across the United States that monitorGPS satellite data. Two master stations, located on either coast,collect data from the reference stations and create a GPS datacorrection message. According to the FAA’s Web site, testing inSeptember 2002 of WAAS confirmed an accuracy performance of 1–2 meters horizontal and 2–3 meters vertical throughout the majorityof the continental United States and portions of Alaska.WAAS is just one service provider that adheres to the MOPS(Minimum Operational Performance Standard) for global SatelliteBased Augmentation Systems (SBAS). Eventually, there are severalservices of worldwide geostationary communication satellites andground reference stations.All SBAS systems use the same receiver frequency; therefore, anyoperational SBAS system should be capable of providing your GPSunit with increased accuracy at any location in the world.Currently, enabling WAAS on your Garmin GPSMAP 276C inregions that are not supported by ground stations might not improveaccuracy, even when receiving signals from an SBAS satellite. Infact it can degrade the accuracy to less than that provided by GPSsatellites alone. For this reason, when you enable WAAS on yourGarmin GPS receiver, the receiver automatically uses the methodthat achieves the best accuracy. To enable WAAS, see page 6.For more information, go to http://gps.faa.gov/Programs/WAAS/waas.jsp.10 GPSMAP 276C Owner’s ManualAPPendIx > sAtellIte InforMAtIon