Reference
18
Driving with Dead Reckoning (2660 Only)
The StreetPilot 2660 comes with dead reckoning capabilities, which means that you continue to get
navigation guidance even if you lose GPS reception, such as when you are travelling in dense urban envi-
ronments with tall buildings and tunnels.
To achieve dead reckoning, the 2660 utilizes an internal angular rate sensor, an external speed sensor
input, and an external reverse light sensor input. A special dead reckoning cable is connected to your
vehicle’s speedometer and backup lights (it must be professionally installed by an authorized Garmin
installer). Thus, when you lose GPS reception, your StreetPilot can acknowledge your turns as well as your
distance travelled while you are driving. In this way, it can continue to accurately give navigation guidance
until your GPS reception returns. Driving with dead reckoning capabilities is so seamless, you will not
even know that you do not have GPS reception.
You can simply unplug the dead reckoning cable from the vehicle adapter if you want to use the
StreetPilot 2660 in another vehicle. It will navigate the same way as the StreetPilot 2620.
Driving with Dead Reckoning
The only way you can tell that your StreetPilot is using
Dead Reckoning is to view the GPS Information page.
See page 56 for more information on GPS.
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