High-precision Gyrosensor; Map Matching; GPS is a position detecting system utilizing the signals - Page 419

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GPS is a position detecting system utilizing the signals 
from GPS satellites deployed by the U.S. Department of 
Defense. The Mobile Navigation System uses input from 
three or more satellites and calculates the vehicle position 
based on the principle of triangulation. 
The positioning accuracy of the system corresponds to the 
error display of the GPS which is from about 30 to 200 meters.

●

If you are using the system for the first time, or if you have not used it for some time, it takes 
about 5 minutes (or about 2 minutes in open areas) to calculate your vehicle’s position.

■

GPS signal reception is poor in the following places

●

The GPS satellites are controlled by the U.S. Defense Department, which may intentionally 
lower positioning accuracy. In such cases, there may be vehicle position deviations.

●

There may be vehicle position deviations for some time until GPS signals are received after 
turning on the ignition.

This function compares your vehicle’s tracking data with the road data on the map 
disc, applies dead reckoning to determine the road you are driving on, and displays 
your vehicle on that road on the map.

●

Intelligent map matching addresses the following problems to achieve high accuracy in 
vehicle positioning.

Position Correction for Elevated Roads

Position accuracy is improved by detecting if the vehicle is 
running on or under an elevated road.

Position Correction for Parking Garages

Position accuracy is improved by detecting if the vehicle is 
driving in an elevated or underground parking garage.

High-precision Gyrosensor

A gyro detects turns with an accuracy of 0.05° per second. 
Combined with a speed sensor, it enables the system to 
display the current vehicle position even where GPS signals 
may be blocked.

●

Using a spare tire in place of the regular one may cause vehicle position deviations.

●

Any difference between the direction which your vehicle actually travels and that shown on 
the map is automatically eliminated by azimuth correction.

GPS

In tunnels

Among high-rise buildings Under elevated roads

In wooded areas

Map Matching

MAZDA3_Navi_EA.book  Page 47  Monday, June 6, 2005  9:39 AM