MITSUBISHI LANCER RALLIART 2012 8.G MMCS Manual
Manufacturer: MITSUBISHI, Model Year: 2012, Model line: LANCER RALLIART, Model: MITSUBISHI LANCER RALLIART 2012 8.GPages: 177, PDF Size: 15.86 MB
Page 11 of 177

GPS Measurement   1-8
GPS Measurement
GPSGPS is the acronym for Global Positioning System.
The MMCS uses GPS satellites that orbit the Earth 
in space at an altitude of approximately 20,000km. 
Electromagnetic waves from at least three of these 
satellites are received on the Earth by the system, 
making it possible to learn the current position.
Map MatchingWhen traveling with just the GPS, there may be errors 
in the current position display. In such case, “map 
matching” is the function that compensates for this 
error by assuming that vehicles travel on roads and 
placing the current position on a nearby road.
GPS antenna positionThe position of the vehicle is determined from the 
weak electromagnetic waves from GPS satellites 
received by the GPS antenna.
mngi263
NOTESince it may not be possible to accurately display the 
vehicle position if the electromagnetic waves from 
the GPS satellite are blocked, be sure to obey the 
following:
carbon to the window glass.
 antenna.
 GPS antenna.
Situations where accurate measurement is not 
possible
In situations such as the following, accurate 
measurement may not be possible.
The US Tracking and Control Center controls the 
satellites. Sometimes the electromagnetic waves are 
stopped during upgrades or repairs to the system.
NOTEsatellites by placing objects on or around the GPS 
antenna.
 of the GPS antenna, as it could prevent accurate 
measurement.
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Page 12 of 177

GPS Measurement   1-9
IntroductionSituations where errors occur in the current 
location and direction
GPS satellite unit is poor.
 States Department of Defense, so sometimes the 
satellite itself intentionally sends incorrect position 
data. The measurement error will increase in this 
kind of situation.
 because the distribution of the GPS satellites is poor 
(when the satellites are aligned in approximately the 
same direction or height). (The best accuracy for 
GPS measurement is when signals are received from 
multiple satellites; a satellite directly over the vehicle 
and others just over the horizon to the north, south, 
east and west.)
 GPS measurement, errors are slightly more likely in 
the horizontal direction.
 vehicle height can be received, but electromagnetic 
waves cannot physically be received from satellites 
positioned lower than the vehicle height (on the far 
side of the Earth). This means that an adequate 
height comparison is not possible.
3D MeasurementWhen valid electromagnetic waves can be received 
from at least four GPS satellites, the 3D positions of 
latitude, longitude and height are calculated.
2D MeasurementWhen valid electromagnetic waves can only be 
received from three or less GPS satellites, the height 
is assumed to be unchanged from the previous 
measurement and the 2D positions of latitude and 
longitude are calculated. If this happens, the accuracy 
of the position is less than with the 3D measurement.
No MeasurementIf no valid electromagnetic waves can be received from 
the GPS satellites, there is no measurement.
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Page 13 of 177

Error in the Current Location   1-10
Error in the Current Location
In situations such as the following, the current 
location may not be correctly displayed.
  (E.g., when transported on a ferry or trailer)
engine
  (E.g., on a turntable in a parking area)
 such as mountain roads with steep inclines
in a straight line or gentle curve
 (E.g., freeways)
 such as in a traf  c jam
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