Navigation Systems - Alpine NVE-N099P Owner's Manual

Preface

Navigation systems

This navigation system uses three different sensing devices to determine the present location
and to track the progress of the vehicle. These three devices are: a GPS (Global Positioning
System) receiver which receives digital signals from the GPS satellites to determine the
current position of the vehicle, a gyroscope which determines which direction the vehicle turns,
and a speedometer pulse sensor which determine how far the vehicle has travelled. Because
this system incorporates a gyroscope and a speed sensor, the system will be able to display
the vehicle's position and track the vehicle's progress even in areas where the GPS signal
may be blocked.
All map data is contained on a removable DVD ROM (sold separately). This system integrates
this unique map database with the sensing devices to automatically plot out a route when a
destination is entered. While driving, the navigation system guides you along the route with
pictorial displays and verbal prompts.
GPS (Global Positioning System)
Delay time before the present vehi-
cle's position can be displayed
Determination of the present vehicle's posi-
tion starts when the ignition key is turned to
the ACC or ON positions and ends when the
key is turned OFF. When the key is first
turned to the ACC or ON positions, there is a
slight delay of approximately one to two
minutes before the present vehicle's position
can be displayed.
Gyroscope
The gyroscope is a sensor that accurately
measures the angle by which the direction of
a vehicle or other moving body changes.
Gyroscopes are used in inertial navigation
systems for airliners and ships. In this
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Preface
This system receives signals from 3 or more
GPS satellites (operated by the United
States Department of Defense) orbiting at an
altitude of 21,000 kilometres and measures
the present car position using the same
principles as triangulation.
The error from the actual position
of the vehicle
When GPS signals can be received from 4
or more satellites, 3 dimensional positioning
(the altitude, latitude, and longitude) of the
vehicle can be determined. In this case, the
error from the actual position of the vehicle is
in the range of 100 to 655 feet (30 to 200
meters). When GPS signals can only be
received from 3 satellites, only two
dimensional positioning (latitude and longitude)
can be determined, resulting in a
slightly increased error. When GPS signals
can only be received from less than three
satellites, positioning of the vehicle through
GPS is not possible. In addition to the inher-
ent errors from GPS, the error rate can
also be increased if the United States
Department of Defense deliberately changes
the accuracy rate.
navigation system, the gyroscope is used
together with the speed sensor, making it
possible to display the position of the vehicle
even in locations where GPS signals may be
blocked.