17
TRACKER 5100/5100i/5500/5500i Installation and Operation Manual
NAVMAN
6 Highway display
The highway display has a bird’s eye view of the
boat’s course to a destination:
To go to the highway display, press DISP and select
Highway.
Warning: The highway display does not show
land, dangerous waters or chart symbols.
CDI lines, parallel to the boat’s plotted course
(see appendix C, CDI). The CDI lines are like a highway
over the water where the boat will move.
Six numeric data fields.
To change what data is displayed, see below.
Boat position is at the bottom, centre of the display.
CDI scale
Boat’s plotted course to destination.
The highway display shows:
Destination waypoint.
Change the numeric data display
1
In the highway display, press MENU and select
Data setup.
2
Change a data field:
i
Press the cursor keys to highlight the field.
ii
Press ENT to display a menu of the data
that can be shown in the field.
iii Select the data to show in the field; select
None to leave the field empty.
3
Repeat the above step to change other fields.
4
Finally, press ESC to return to the highway
display.
GPS worldwide navigation
The US Government operates the GPS system. Twenty-
four satellites orbit the earth and broadcast position and
time signals. The positions of these satellites are
constantly changing. The GPS receiver analyses the
signals from the closest satellites and calculates exactly
where it is on earth. This is called the GPS position.
The accuracy of the GPS position is typically better than
10 m (33 ft) for 95% of the time. A GPS antenna can
receive signals from the GPS satellites when it is almost
anywhere on earth.
GPS antennas
TRACKERs 5500i and 5100i have built in GPS antennas;
TRACKERs 5500 and 5100 are usually connected to
the external GPS antenna supplied. All TRACKERs have
a sensitive 12-channel receiver built in. The receiver
tracks signals from all satellites visible above the horizon
and uses measurements from all satellites more than
5° above the horizon to calculate the position.
7 Satellites
DGPS
A DGPS system uses correction signals to remove some
of the errors in the GPS position. The TRACKER can
use one of two types of DGPS system:
WAAS and EGNOS DGPS
WAAS and EGNOS are two satellite based DGPS
systems. The correction signals are broadcast by
satellites and are received by the TRACKER’s
standard GPS antenna. The accuracy of the
corrected GPS position is typically better than 5 m
(16 ft) for 95% of the time.
WAAS covers all of the USA and most of Canada.
EGNOS will cover most of Western Europe when
it becomes operational about the end of 2003. To
enable WAAS and EGNOS DGPS, (see
section 13-3).
Differential beacon DGPS
Differential beacons are land based radio
transmitters that broadcast correction signals
