Pioneer F77 Operations Manual download pdf (Page 216)

Map matching

As mentioned, the positioning systems used

by this navigation system are susceptible to

certain errors. Their calculations may, on occa-

sion, place you in a location on the map where

no road exists. In this situation, the processing

system understands that vehicles travel only

on roads, and can correct your position by ad-

justing 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

functions may not work properly, and the error

may become bigger.

When positioning by GPS is

impossible

! GPS positioning is disabled if signals can-

not be received from more than two GPS

satellites.

! 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 en-

closed parking

garages

Under elevated

roads or similar

structures

When driving

among high build-

ings

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.

! Do not cover the GPS aerial with spray

paint or car wax, because this may block

the reception of GPS signals. Snow buildup

can also degrade the signals, so keep the

aerial clear.

p If a GPS signal has not been received for a

long time, your vehicle ’s actual position

and the current position mark on the map

may diverge considerably or may not be up-

dated. In such case, once GPS reception is

restored, accuracy will be recovered.

Engb

216

Appendix

Appendix

1 2 ... 211 212 213 214 215 216 217 218 219 220 221 ... 239 240

Comments to this Manuals

No comments