Raymarine e7 User Reference page 300

Item Description
1 Sky view — a visual representation of the position of tracked
satellites.
2 Satellite status — displays the signal strength and status of
each satellite identified in the sky view diagram on the left of the
screen. The colored bars have the following meanings:
• Grey = searching for satellite.
• Green = satellite in use.
• Orange = tracking satellite.
3 Horizontal Dilution of Position (HDOP) — a measure of
GPS accuracy, calculated from a number of factors including
satellite geometry, system errors in the data transmission and
system errors in the GPS receiver. A higher figure signifies a
greater positional error. A typical GPS receiver has an accuracy
of between 5 and 15 m. As an example, assuming a GPS
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 GPS 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.
4 Fix status — indicates the actual mode the GPS receiver is
reporting (No Fix, Fix, D Fix or SD Fix).
5 Mode — the mode currently selected by the GPS receiver.
6 Datum — The GPS receiver's datum setting affects the
accuracy of the vessel position information displayed in the chart
application. In order for your GPS receiver and multifunction
display to correlate accurately with your paper charts, they must
be using the same datum.
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The accuracy of the GPS receiver depends on the parameters
detailed above, especially the azimuth and elevation angles which
are used in triangulation to calculate your position.
Multiple data sources (MDS) overview
Installations that include multiple instances of data sources can
cause data conflicts. An example is an installation featuring more
than one source of GPS data.
MDS enables you to manage conflicts involving the following types
of data:
• GPS Position.
• Heading.
• Depth.
• Speed.
• Wind.
Typically this exercise is completed as part of the initial installation,
or when new equipment is added.
If this exercise is NOT completed the system will automatically
attempt to resolve data conflicts. However, this may result in the
system choosing a source of data that you do not want to use.
If MDS is available the system can list the available data sources
and allow you to select your preferred data source. For MDS to be
available all products in the system that use the data sources listed
above must be MDS-compliant. The system can list any products
that are NOT compliant. It may be necessary to upgrade the
software for these non-compliant products to make them compliant.
Visit the Raymarine website (www.raymarine.com) to obtain the
latest software for your products. If MDS-compliant software is not
available and you do NOT want the system to automatically attempt
to resolve data conflicts, any non-compliant product(s) can be
removed or replaced to ensure the entire system is MDS-compliant.
e7 / e7D — User reference