Handling Large Errors; When The Positioning By Gps Is Impossible - Pioneer AVIC-HD3II Operation Manual

Appendix
Appendix
p If ND-PG1 is used or if your vehicle is oper-
ating in Simple hybrid mode, the distance
calculation value cannot be replaced auto-
matically.
Map matching
As mentioned, the GPS and dead reckoning
systems used by this navigation system are
susceptible to certain errors. Their calcula-
tions may, on occasion, place you in a location
on the map where no road exists. In this situa-
tion, the processing system understands that
vehicles travel only on roads, and can correct
your position by adjusting it to a nearby road.
This is called map matching.
With map matching
Without map matching

Handling Large Errors

Positioning errors are kept to a minimum by
combining GPS, Dead Reckoning, and map
matching. However, in some situations, these
174
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functions may not work properly, and the error
may become bigger.
When the positioning by GPS is
impossible
! If signals cannot be received from more
than two GPS satellites, GPS positioning
does not take place.
! In some driving conditions, signals from
GPS satellites may not reach your vehicle.
In this case, it is impossible for the system
to use GPS positioning.
In tunnels or enclosed parking garages
Under elevated roads or similar struc-
tures
When driving among high buildings
When driving through a dense forest or
tall trees
! If a car phone or mobile phone is used near
the GPS aerial, GPS reception may be lost
temporarily.