TravRoute CoPilot 2002 - Manual (Page 7)

About GPS Technology
The Global Positioning System (GPS) is a tracking and navigation system developed by the
U.S. Department of Defense. The system uses 24 satellites that orbit the earth, sending out
radio waves that can be picked up by GPS sensors (hardware devices for receiving data).
Normally, a GPS sensor relies on receiving signals from four satellites simultaneously to
track its position. Each signal contains an identifier for the satellite that emitted it and the
exact time it was emitted (to the nanosecond). GPS relies on the fact that radio waves travel
at the speed of light to calculate distances and the exact location of the sensor is figured by
combining the data received from three or four satellites.
Given the right conditions, a GPS sensor can identify your geographic position anywhere in
the world. GPS is able to give you the latitude, longitude and elevation of your present
location, as well as your road speed and direction of travel on a route.
GPS Accuracy
The GPS signal CoPilot receives from the constellation of satellites has a rated accuracy of
10 meters. This means that 95% of the time the reported location is within 10 meters (30
feet) of your exact position. CoPilot takes this location information and enhances it further
by "snapping" it to our street and highway network. Occasionally, CoPilot will place you on
the wrong road. If this occurs, keep driving and CoPilot will automatically correct itself and
find your proper position.
At times, CoPilot's GPS tracking will be less accurate or fail to work at all because the unit
is unable to receive satellite signals. However, the unit is resilient; eventually, it finds itself.
Its ability to report your location is directly proportional to its ability to receive accurate
line-of-sight satellite signals. Heavy foliage, buildings, or any other structures
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WARNING:
CoPilot navigation instructions are only computer-generated advisories
and may contain errors. Obey all traffic regulations even if they are
completely contradictory to the navigation suggestions. Keep your eyes
on the road and hands on the wheel! Do not attempt to look at the
screen if you are the driver. TravRoute ® assumes no responsibility for
any damage or injury resulting from the use of this product.