Operation Outside The Memorised Area; Positioning Technology; Positioning By Gps; Positioning By Dead Reckoning - Pioneer AVIC-D3 Operation Manual

MAN-AVIC-D3-EN.book Page 121 Monday, January 15, 2007 8:51 AM
RDS-TMC function. Touching
you to check the locations of the traffic infor-
mation along the route. However, you cannot
perform rerouting.
Operation outside the memo-
rised area
When the vehicle leaves the memorised area, the
functions will be limited.
• The auto reroute function does not work.
• You can only display a larger scale map. The
map display will automatically change to a
50 km (or 100 km) scale.
• The map matching function will not be availa-
ble. Therefore, the position of your vehicle may
be misaligned.
• The navigation guidance will only be available
when arriving at your destination. Other guid-
ance is not possible (this includes no display of
direction arrows).
To cancel these limitations, insert the DVD Map
Disc to the navigation system.

Positioning Technology

The navigation system accurately measures your
current location by combining the positioning by
GPS and by Dead Reckoning.

Positioning by GPS

The Global Positioning System (GPS) uses a net-
work of satellites orbiting the Earth. Each of the
satellites, which orbit at a height of 21 000 km,
continually broadcasts radio signals giving time
and position information. This ensures that sig-
nals from at least three can be picked up from
any open area on the earth's surface.
The accuracy of the GPS information depends on
how good the reception is. When the signals are
strong and reception is good, GPS can determine
latitude, longitude and altitude for accurate posi-
tioning in three dimensions. But if signal quality
is poor, only two dimensions, latitude and longi-
tude, can be obtained and positioning errors are
somewhat greater.
allows

Positioning by dead reckoning

The 3D Hybrid Sensor in the navigation system
also calculates your position. The current loca-
tion is measured by detecting driving distance
with the speed pulse, the turning direction with
the Gyrosensor and inclination of the road with
the G sensor.
The 3D Hybrid Sensor can even calculate
changes of altitude, and corrects for discrepan-
cies in the distance travelled caused by driving
along winding roads or up slopes. Also, the navi-
gation system learns the driving conditions and
stores information in the memory. Thus, as you
drive more, the precision of the positioning
becomes more accurate.
The method of positioning changes as follows
depending on whether the speed pulse of your
vehicle is detected or not:
3D hybrid mode
This is active when the speed pulse is detected.
Inclination of a road can be detected.
Simple hybrid mode
When the speed pulse is not detected, position-
ing is performed in this mode. Only horizontal
movement is detected, so it becomes less accu-
rate. Also, when the positioning by GPS is not
available, such as when your vehicle enters a
long tunnel, the discrepancy between your actual
and calculated position may become bigger.
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