Magellan Trailblazer, Справочное руководство

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First-Time GPS Users
This section is to help readers who are new to navigation or to electronic
navigation equipment. lt explains terms that are commonly used by naviga-
tors worldwide and some basic concepts of navigation, such as position fixes
and coordinates.
Navigation
Navigation is getting from one place to another. lt is also knowing where you
are in relation to the path between those locations. At its most basic,
navigation is getting from here to there and home again. At its most
advanced, navigation has been called both an art and a science.
In the past, people left markers — blazes cut into trees, sticks laid out in a
particular pattern, or even small piles of stones — to mark a location or to
show the correct path to an important position. Later, these paths were
charted. This eventually developed into the maps and charts we use today.
Today, markers can be made electronically with a GPS receiver, even at sites
that do not permit leaving physical marks, such as on a lake. You can mark
a path even in featureless terrain by making electronic blazes (called
waypoints) and storing them in the receiver's memory. These electronic
markers can be used to return to your starting position, and can be reused
again and again.
All you have to do to make full use of this wizardry is become familiar with
a few terms and what they mean.
Latitude and Longitude
A
position
is a location that can be
described in a unique, numerical
way. The format that is used to
describe a position is called a coor-
dinate system. The most common
coordinate system in use today is
Latitude/Longitude (Lat/Lon).
Lat/Lon projects lines of latitude (par-
allels) and lines of longitude (merid-
ians) onto the earth. Lines of lati-
tude are the equator and the hori-
zontal lines that are "parallel" to it. Lines of longitude are the vertical lines
that are perpendicular to the equator and pass through the poles. A position
is described as the intersection of a line of latitude and a line of longitude.
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