WAAS is a GPS navigation system with differential correction by means of
geostationary satellites. The US FAA has been testing this system and expects
more field tests in 2003. Similar systems, using Satellite-Based Augmentation
Systems (SBAS), are under development in Japan (MSAS: MSAT Satellite-based
Augmentation System) and Europe (EGNOS: European Geostationary Navigation
Overlay System). They are said to be fully interoperable and compatible. MSAS and
EGNOS are expected to become fully operational in 2004 or after.
As the WAAS utilizes the same frequency as the GPS, a single antenna can receive GPS and WAAS signals. Currently
two Inmarsat GEO satellites are available for receiving the WAAS signal: AOR-W and POR. Major contributors of an
error in a single frequency GPS system are receiver clock drift and signal delays by refraction. The WAAS reference
stations on the earth monitor the GPS constellation and route GPS error data to the satellites via the master earth
station. The Inmarsat or communication satellite broadcasts the differential corrections to marine and aviation users.
Choose from two units that accept either
Furuno MiniChart and Navionics
®
Nav-
Chart
or C-MAPNT Charts
.
Own ship
Planned route
Own ship's
track
Cursor
Navionics
®
Nav-Chart
Compact
sensitive
GPS/DGPS
antenna
WAAS
(Wide Area Augmentation System)
GPS/DGPS /WAAS
combo antenna
For all boaters...
FURUNO GP-1650 series offer
Accurate Positioning with WAAS,
High Contrast Bright LCD for optimum viewing
under the direct sun light
