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How Reliable is CoPilot?
The CoPilot map database is remarkably accurate, providing comprehensive, detailed street 
information.  From the most populated cities to the smallest hamlets, CoPilot map data has been 
created to support your travels wherever they may take you.  
Data Corrections
ALK continually updates the CoPilot map database as we strive to provide you with the 
highest quality product.  If you encounter missing or inaccurate map data, please contact us 
and let us know so that we can include it in our updates.  See Data Corrections p. 63 for 
complete instructions.
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, tunnels, or any other structures 
obstructing satellite communications will interfere with CoPilot's ability to track your 
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