Magellan NAV 5000, Руководство пользователя

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CHAPTER 1
INTRODUCTION
1-1
This chapter contains a description of the NAV 5000, its specifications
and accessories, and the Global Positioning System (GPS).
THE NAV 5000
The NAV 5000 is an affordable, hand-held GPS receiver that is fast,
powerful, and accurate, yet very easy to use. The NAV 5000 uses five
channels working simultaneously to locate and collect data from the
GPS satellites. The unit's gallium arsenide circuitry rapidly processes the
data received from the satellites to compute current location (LAT/
LON), altitude, and velocity and navigation data in under 1 minute, and
updates the data every second.
The NAV 5000 can be set to use any of three modes to calculate
positions: two-dimensional (2D), three-dimensional (3D), and the
Automatic (AUTO) Mode. In 2D, the unit uses 3 satellites to calculate
latitude and longitude: altitude is a user-entered variable. In 3D, the
unit uses 4 satellites to calculate latitude, longitude, and altitude. In the
Automatic Mode, the unit uses 3D whenever 4 satellites are available;
when only 3 satellites are available, the unit switches to 2D.
The NAV 5000 also stores an initial position, last fix, the four most
recent fixes, and up to 100 waypoints that are created by the user.
Most of these positions can be used to enter a route and to estimate
the coordinates and bearing of a distant location.
The NAV 5000 was developed primarily for marine use. lt supports
most devices that conform to NMEA (National Marine Electronic
Association) standards 0180 or 0183. This includes devices such as
autopilots, plotters, and sounders.
Though a fast, powerful navigation tool, the NAV 5000 is very easy to
use. Most functions can be accessed by pressing only one clearly
marked key. Other functions, such as the NMEA control and Sat
Status, are accessed through the auxiliary keys.