About Gps - Garmin eMap Owner's Manual

Reference

About GPS

The Map page is the main
operating page of the eMap. It
provides position, direction,
distance, map features, speed,
time and location
information.
The Map Page can be
expanded to fill the full
display area, oriented to
either North or to Track Up
to match your direction of
travel. You can change the
map scale by Zooming In or
Zooming Out. You can
customize the way in which
map details are displayed.
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The Global Positioning System (GPS) is a system of
24 satellites which circle the earth twice a day in a very
precise orbit and transmit information to earth. The
eMap must continuously "see" at least three of these
satellites to calculate your position and track your
movement. At times, additional satellites may be needed
to determine a position.
By using an almanac (a timetable of satellite
numbers and their orbits) stored in the receiver' s
memory, the eMap can determine the distance and
position of any GPS satellite and use this information to
compute your position.
The Map Page is the main operating page of the
eMap. All system programming and options are designed
to support navigation activity using the Map Page.
The Map Page shows your movement using a real-
time track log (an electronic bread crumb trail that
appears directly on the map as you're traveling), and
your present position as a triangle 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.
The map can be oriented with the top of the page
always pointing north 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. Refer to
the section titled GPS Info Page.
Nearby waypoints are depicted on the map with any
one of over 50 different symbols, with the waypoint
name shown directly above the symbol. We'll cover more
about the eMap' s waypoint features and the Map Page in
this reference section.