Raymarine c125, Installation And Operation Instructions Manual

Page: 105 / 464

including satellite geometry, system errors in
the data transmission and system errors in the
receiver. A higher figure signifies a greater
positional error. A typical receiver has an accuracy
of between 5 and 15 m. As an example, assuming
a receiver error of 5 m, an HDOP of 2 would
represent an error of approximately 15 m. Please
remember that even a very low HDOP figure is
NO guarantee that your receiver is providing an
accurate position. If in doubt, check the displayed
vessel position in the Chart application against
your actual proximity to a known charted object.
• Estimated Horizontal Position Error (EHPE)
— EHPE is a measure of the estimated error of
a position fix in the horizontal plane. The value
displayed indicates that your position is within a
circle radius of the stated size 50% of the time.
• Fix status — indicates the actual mode the
receiver is reporting:
– Fix — Satellite fix has been acquired.
– No Fix — No satellite fix can be acquired.
– D Fix — A differential beacon fix has been
acquired.
– SD Fix — A differential satellite fix has been
acquired.
• Position — Displays the latitude and longitude
position of your receiver.
• Date / Time — Displays the current date and time
generated by the position fix in UTC format .
• Mode — Identifies wether the receiver is working
in differential mode or non-differential mode.
• Datum — The receiver's datum setting affects
the accuracy of the vessel position information
displayed in the Chart application. In order for your
receiver and MFD to correlate accurately with your
paper charts, they must be using the same datum.
Global Navigation Satellite Systems (GNSS)
A GNSS is a system of satellites that provides
autonomous geo-spatial positioning that allows
electronic devices with compatible receivers to
determine their location (longitude, latitude and
altitude).
Operational GNSS
• GPS (NAVSTAR) Global Positioning System
US owned constellation of satellites that became
fully operational in 1995.
• GLONASS acronym for " GLO balnaya
NA avigatsionnaya S putnikovaya S istema " or
“Global Navigation Satellite Systems”
Russian owned constellation of satellites that
offered global coverage in 2010.
Planned GNSS
• Galileo
European satellite constellation in initial
deployment phase due to become operational in
2020.
• COMPASS / Beidou-2
Chinese Regional Navigation Satellite System
(Beidou) is currently being expanded for global
coverage (COMPASS or Beidou-2) by 2020.
Satellite based augmentation systems
(SBAS)
Satellite based augmentation systems (SBAS) are
systems that are used to compliment existing GNSS
by providing differential corrections that improve a
GNSS’s attributes such as accuracy, availability and
reliability.
The image below shows SBAS regional coverage.
W AAS
EGNOS
GAGAN
MSAS
D13121-1
• WAAS — Wide Area Augmentation System
(Operated by the Federal Aviation Authority (FAA)
in the USA.)
• EGNOS — European Geostationary Navigation
Overlay Service (Operated by the European
Space Agency.)
• GAGAN — GPS Aided Geo Augmented
Navigation (Operated by India.)
• MSAS — Multi-functional Satellite Augmentation
System (Operated by Japan’s Ministry of Land,
Infrastructure and Transport and Japan Civil
Aviation Bureau (JCAB)
• QZSS — Quasi-Zenith Satellite System (Proposed
by Japan)
Raymarine GPS / GNSS receiver compatibility
Raymarine GPS receivers and GNSS
(GPS/GLONASS) receivers are compatible
with the following GNSS and SBAS.
Status /
Type
Name Compatible receivers
Oper-
ational
GNSS GPS All internal and external Raymarine
GPS receivers and GNSS receivers
Oper-
ational
GNSS GLON-
ASS a9x and a12x internal GNSS
receiver
Planned
GNSS COM-
PASS /
Beidou–2 * a9x and a12x internal GNSS
receiver
Planned
GNSS Galileo * a9x and a12x internal GNSS
receiver
Oper-
ational
SBAS WAAS
All internal and external Raymarine
GPS receivers and GNSS receivers
Getting started
105