sat nav TOYOTA SIENNA 2007 Service Repair Manual

NS–4NAVIGATION – NAVIGATION SYSTEM
NS
2. Navigation system outline
(a) Vehicle position tracking methods
It is essential that the navigation system correctly
tracks the current vehicle position and displays it on
the map. There are 2 methods to track the current
vehicle position: autonomous (dead reckoning) and
GPS* (satellite) navigation. Both navigation
methods are used in conjunction with each other.
*GPS (Global Positioning System)
E120052E01

NAVIGATION – NAVIGATION SYSTEMNS–7
NS
(c) GPS navigation (Satellite navigation)
This method detects the absolute vehicle position
using radio waves from a GPS satellite.
* GPS satellites were launched by the U.S.
Department of Defence for military purposes.
Number of satellites Measurement Description
2 or less Measurement impossibleVehicle position cannot be obtained because
the number of satellites is not enough.
3 2-dimensional measurement is possibleVehicle position is obtained based on the
current longitude and latitude. (This is less
precise than 3-dimensional measurement.)
4 3-dimensional measurement is possibleVehicle position is obtained based on the
current longitude, latitude and altitude.
I100029E03

NAVIGATION – NAVIGATION SYSTEMNS–9
NS
(e) Touch switch
Touch switches are touch-sensitive (interactive)
switches operated by touching the screen. When a
switch is pressed, the outer glass bends in to
contact the inner glass at the pressed position. By
doing this, the voltage ratio is measured and the
pressed position is detected.
3. DVD (Digital Versatile Disc) player outline (for
navigation map)
(a) The radio and navigation assembly (built-in
navigation ECU) uses a laser pickup to read the
digital signals recorded on a DVD.
HINT:
• Do not disassemble any part of the radio and
navigation assembly (built-in navigation ECU).
• Do not apply oil to the radio and navigation
assembly (built-in navigation ECU).
• Do not insert anything but a DVD into the radio
and navigation assembly (built-in navigation
ECU).
E106414E03