Garmin GPSMAP 278 - Manual (Page 117)

What is EGNOS/WAAS/MSAS?
The European Geostationary Navigation Overlay System (EGNOS)
is European Space Agency developed service to improve the overall
integrity of the GPS signal and increase position accuracy for users
in Europe. In North America, EGNOS is referred to as WAAS.
The system is made up of satellites and network of ground reference
stations positioned across Europe that monitor GPS satellite data.
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 EGNOS/WAAS on your Garmin GPSMAP 278
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 EGNOS/WAAS
on your Garmin GPS receiver, the receiver automatically uses the
method that achieves the best accuracy. To enable EGNOS/WAAS,
see to page 6 .
LORAN TD Setup
LORAN C is a radio navigation aid operated and maintained in the
United States by the United States Coast Guard. LORAN
(LOng RAnge Navigation) system covers the entire United States
and the U.S. Coastal Confluence Zone. From the perspective of a
mariner, the system is used for ocean and coastal navigation. It can
be used as a supplemental system for harbor and harbor approach
navigation, and it is used for inland navigation by recreational
vehicles.
LORAN TD Feature
The LORAN TD (Time Delay) feature eases the transition from
using LORAN to using GPS. The GPSMAP unit automatically
converts GPS coordinates to LORAN TDs for those who have a
collection of LORAN fixes for favorite fishing spots and other
waypoints recorded as TDs. You can display your location as a TD
or enter waypoints as TDs. The accuracy to be expected from this
conversion is approximately 30 meters. When the unit is placed
in the LORAN TD format mode, it simulates the operation of a
LORAN receiver. Position coordinates might be shown as TDs,
and all navigation functions may be used as if the unit was actually
receiving LORAN signals.
GPSMAP 278 Owner’s Manual 0
A
PPendIx
> W
hAt Is
egnos/WAAs/MsAs
And
lorAn td s
etuP