9
Locations where GPS signals are received easily
Locations where GPS signals cannot be received
GPS signals cannot be received in areas listed below. However, the gyroscope and
speed sensor will continue to provide data to track the vehicle’s progress along the route
without interruption.
GPS signals are received best in areas
where there are no tall buildings, trees,
or other tall objects that can obstruct the
signals.
In tunnels and indoor
parking lots
Locations surrounded
by tall buildings
Locations surrounded
by tall trees
On the bottom level of
double-decker express-
ways
When a GPS satellite is low on the horizon (angle
below 10°), obstructions sometimes make normal
reception impossible
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 navi-
gation system, the gyroscope is used to-
gether with the speed sensor, making it
possible to display the present position of the
vehicle even in locations where GPS signals
may be blocked.
