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Let’s start with the Satellite Status Page, which is the page you’ll view while your
unit is getting a position fix. If you’re not already on this page, press PAGE or QUIT
until it appears. The Satellite Status Page shows you status information that helps
you understand what the receiver is doing at any given time, and it’s a page that
you’ll want to occasionally refer back to as you use your unit. It features a sky view
of available satellites, corresponding signal strength bars, the status of your current
position fix (acquiring, 2D, 3D, etc.), and your estimated position error (EPE). You
can also tell how much battery power is remaining, and you can adjust the screen
contrast by pressing the rocker keypad.
Satellites are indicated on the sky view and the signal strength bars by their cor-
responding number, from 01 through 32. The sky view shows where it is looking in
the sky for each satellite, by indicating the direction and elevation (angle above the
horizon). The signal strength bars depict the relative strength of the signal from each
satellite being received. The taller the bar, the stronger the signal.
The signal strength bars give
you an indication of what
satellites are visible to the
receiver, whether or not they’re
being used to calculate a posi-
tion fix, and the signal quality.
If satellite reception is lost, or
an insufficient number of
satellites are available, you
will be alerted with a ‘Poor
Coverage’ receiver status and
Satellite Status Page
Satellite Status Page
IndicatorSignal Strength BarSky View
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The Position Page shows you where you are, what direction you’re heading, and
how fast you’re going—and it’s the page you’ll want to use when you don’t have a
A graphic compass display at the top of the page shows your direction of travel
(track) while you’re moving, while six user-selectable data fields below display your
current speed, average speed, trip odometer, trip timer, and sunrise/sunset times at
your current position. “User-selectable” means you can change them to display other
information. We’ll cover these fields more in the reference section.
Below the user-selectable data fields are additional data fields to display your
current position, along with current time and date. The current position readout can
be in latitude/longitude, UTM/UPS, Maidenhead or one of several regional grids.
Current time and date can be in local time or UTC (Coordinated Universal Time).
Position Page showing UTM
coordinates for use with
USGS topographic maps, etc.
The trip odometer, trip timer
and average speed readings
can all be reset from the ‘Trip
Computer’ option on the Main
Menu. See page 66.
Position Page Track Compass
and Date Current Position
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The Map Page shows your movement using a real-time track log (an electronic
breadcrumb trail that appears directly on the map as you’re traveling), and your
present position as a pointer icon in the center of the map. The Map Page also shows
any nearby lakes, rivers, highways and towns. Use the zoom keys (IN and OUT) to
adjust the map to the desired scale.
To change the map scale:
1. Press the IN zoom key to select a smaller scale and more detail for a smaller area.
2. Press the OUT zoom key to select a larger scale and display a larger area.
The map can be oriented with the top of the page always pointing north,
oriented along your desired course, or it can automatically rotate to keep your
current direction of travel (track) at the top of the screen. The default setting is
‘North Up’, which keeps the top of the page always pointing north.
Nearby waypoints are depicted on the map with any one of over 40 different
symbols, with the waypoint name shown directly above the symbol. We’ll cover
more about the GPS III’s waypoint features and the Map Page in the reference
section of this manual.
With the map oriented to
‘track up’, the pointer always
points up and the map rotates
to your current direction of
travel (track). Note the north
indicator on the map.
You can also select a full-
screen map from the Map
Page Options. See page 35.
Map Page Present PositionData Fields
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The GPS III features two different navigation pages: Compass and Highway. The
Compass Page is first. This page provides graphic steering guidance to a destination
waypoint, with an emphasis on the bearing to your destination and current direction
of travel. (The Highway Page places greater emphasis on the straight-line desired
course and the distance and direction you are off course.) The middle of the page fea-
tures a rotating ‘compass ring’ that shows your course over ground (track) while you’re
moving, and a bearing pointer that indicates the direction of the destination (bearing)
relative to the course over ground. The compass ring and pointer arrow work inde-
pendently to show—at a glance—the direction of your movement and the direction to
your destination. For instance, if the arrow points up, you are going directly to the
waypoint. If the arrow points any direction other than up, turn toward the arrow until
it points up—then continue in that direction.
The current speed and distance to the destination waypoint are displayed at the
top of the screen. The bottom of the page displays the time to the destination
waypoint and the current time. This page provides better steering guidance than the
Highway Page when travelling at slower speeds and/or when making frequent
If the bearing pointer points
up, your are going directly to
your destination. If not, turn
toward the arrow until it
points up, then continue in
The ‘Big Numbers’ option
(available from the Compass
Page Options) shows a much
smaller compass display and
larger data field characters.
See page 39.
Compass Page Compass Ring
and Distance to
Time to Waypoint
and Current Time
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The GPS III’s Highway Page also provides graphic steering guidance to a destina-
tion waypoint. As you head toward your destination, the middle of the screen pro-
vides visual guidance to your waypoint on a moving graphic “highway.” Your present
position is at the bottom center of the highway display. The line down the middle of
the highway represents your desired course. As you navigate toward a waypoint, the
highway will actually move—indicating the direction you’re off course. To stay on
course, simply move toward the center of the highway.
The top of the page indicates speed and distance to your destination (or the next
waypoint in a route), along with a track compass showing current direction of
travel. Directly below the distance reading is the time required to reach your desti-
nation (or the next waypoint in a route), in hours/minutes or minutes/seconds. The
pointer at the bottom of the page also shows the bearing to your destination, relative
to your current track. If the pointer points straight ahead, you’re heading directly to
Use the Highway Page as your primary navigation page (in lieu of the Compass
Page) when your main concern is following a defined course.
If you move off course the
highway display will move,
indicating the direction you
are off course. To stay on
course, simply move toward
the center of the highway.
As you approach your desti-
nation, the graphic highway
will stop at the destination
waypoint. You have arrived
when the waypoint is at the
bottom center of the display.
Destination (or Next
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