Fujitsu AVN2454 Car Video System User Manual


 
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3. Accuracy and error
Helpful tips
Positioning accuracy
The GPS is a very accurate satellite controlled by the U.S. Department of Defense. Errors
may result due to the occurrence of a multipath caused by reflections off buildings or other
structures.
GPS signal quality and reception conditions
Any obstruction coming between the satellite and the GPS antenna will disrupt signal
reception from the satellite. Also, 3 or more signals must be received simultaneously to
enable positioning. When driving along locations such as those shown below, GPS
positioning is not possible.
In addition, obstructions placed on or near the GPS antenna (such as a load) will disrupt
signals from the satellite.
Because the GPS satellite orbits the earth, signal reception conditions may vary
depending on the position of the satellite even if driving in the same area. Signals from a
satellite orbiting near the horizon are more likely to be obstructed.
The GPS satellite is controlled by the U.S. Department of Defense and can be
deliberately made to lose positioning accuracy.
Underground, in a tunnel or
in an indoor parking structure
Surrounded by obstructions
such as tall buildings
Densely wooded areas Under an elevated road
In a building
On a cliffside road or at a
cavern opening