Port Tunnel Navigation

eirman

When I used my Nuvi 760 in the tunnel a few years ago I got a "no satellite sigmal" message the whole way through.

I tried it again quite recently and it now works the whole way through.

Does anyone know if this is predictive navigation based on a software update or is the satellite signal somehow beamed into the tunnel?

(I hadn't got the nerve to stop and see!)

KoolKid

Tom Tom use EPT which is basically the device using its best judgement based on history , speed & time etc..
I'm sure Garmin devices are using the same technology.

The Swordsman

eirman wrote: »

When I used my Nuvi 760 in the tunnel a few years ago I got a "no satellite sigmal" message the whole way through.

I tried it again quite recently and it now works the whole way through.

Does anyone know if this is predictive navigation based on a software update or is the satellite signal somehow beamed into the tunnel?

(I hadn't got the nerve to stop and see!)

Sat navs work by picking up signals from three or four satellites and calculates your position based on these signals. I'd imagine to put something in the tunnel to circumvent this system (if it is possible) would be quite expensive. And it would also be pointless - there is only one route once you're in there. If you've taken a wrong turn, you can't do anything until you get out the other end.

I used my Nuvi 265 (with the latest updates) in France during the summer. Drove to Monaco which involved going through a number of tunnels and lost the signal each time. So probably not an software update either.

So maybe, as koolkid said, Garmin use similar software to TomTom and the SatNav has a good memory.

eirman

If it works now and didn't work a few years ago, it must be a software update.