Appendix
Appendix
!The navigation guidance will only be avail- able when arriving at your destination.
Other guidance is not possible (this in- cludes 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 posi- tioning by GPS and by Dead Reckoning.
Positioning by GPS
The Global Positioning System (GPS) uses a network of satellites orbiting the Earth. Each of the satellites, which orbit at a height of
68 900 000 feet (21 000 km), continually broad- casts radio signals giving time and position in- formation. This ensures that signals from at least three can be picked up from any open area on the ground’s surface.
The accuracy of the GPS information depends on how good the reception is. When the sig- nals are strong and reception is good, GPS can determine latitude, longitude and altitude for accurate positioning in three dimensions. But if signal quality is poor, only two dimen- sions, latitude and longitude, can be obtained and positioning errors are somewhat greater.
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 discre- pancies in the distance traveled caused by driving along winding roads or up slopes. Also, the navigation system learns the driving conditions and stores information in the mem- ory. 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 de- tected. Inclination of a street can be detected.
Simple hybrid mode
When the speed pulse is not detected, posi- tioning is performed in this mode. Only hori- zontal movement is detected, so it becomes less accurate. Also, when the positioning by GPS is not available, such as when your vehi- cle enters a long tunnel, the discrepancy be- tween your actual and calculated position may become bigger.
pThe speed pulse data comes from the speed sensing circuit. The location of this speed sensing circuit depends on your ve- hicle model. In some cases, it is impossible to make a connection to it, and in such a case we recommend that
