Amusing experience with built-in Navigation

Reply Subscribe

Thread Tools

Search this Thread

Dec 26, 2008 | 08:15 PM

Mobilehavoc

Thread Starter

AudiWorld Senior Member

Joined: May 2008

Posts: 972

Likes: 12

From: Jersey City, NJ

Amusing experience with built-in Navigation

So was driving from Manhattan (NYC) back to New Jersey a few days ago with the wife and had the Navigation map up on MMI for no apparent reason. I entered the Holland Tunnel and was surprised to see the marker on the navigation map continue to move while the car was underground and there was obviously no satellite reception. My wife uses a Nuvi 780 in her car and I'm so used to the "Lost satellite reception" and utter confusion that unit goes through when in a tunnel or under an extended overpass.

So I noticed on the map it has the border of NJ/NY which is basically right in the middle of the Hudson River, the same river I was driving underneath. I drove while paying attention to the car marker on the Nav and as the marker got really close to the NY/NJ border on the map I looked around and right there in the tunnel was the NY/NJ border marked on the wall!! Exactly at the right spot.

I know this is trivial but I thought (so did my wife) it was pretty cool since it had been stop/go traffic in the tunnel and the car had kept track of the exact position on the map using speed/distance or whatever readings it uses. I expected it to keep track but not this accurate!

Anyway, thought I'd share.

Dec 26, 2008 | 08:55 PM

scottacus

Audiworld Member

Joined: Nov 2008

Posts: 527

Likes: 2

From: Where LA meets the Pacific

Feature is called dead reckoning - underappreciated part of factory nav units

"Dead reckoning" is a feature on most factory nav systems - the nav uses the car computer's electronics to assess distance traveled (basically it keeps track of the odometer) to improve tracking of your position and to keep track of you when you're out of satellite range. Because it's using the odometer to keep track it's pretty accurate (to within a few feet).

Some newer Garmin and TomTom units have an accelerometer to keep track of distance traveled when you're out of satellite range, but its still not as accurate.

Dec 27, 2008 | 07:39 AM

theanimala

AudiWorld Member

Joined: Jul 2001

Posts: 537

Likes: 6

Always been this way on factory nav systems

My 98 Lexus GS400, a 10 year old nav system, does the same thing. I do the exact same thing as you and watch for the line every time I go through the tunnel, which is at least once a month for me.

Dec 27, 2008 | 02:40 PM

urcovrd

AudiWorld Member

Joined: Dec 2008

Posts: 311

Likes: 0

Re: Amusing experience with built-in Navigation

This is what bugs about people who get nav. You know where the hell you are while at the same time love amazing yourself at something telling you where you are/going??? Man now I agree gps is essential when offroading or hiking the Alps but come on people, I've been driving w/o it for 20 years and don't think getting it now will help us to get from point A to point B anymore efficiently then a well planned out road trip with a map of where I'm going (it has the advantages of being there for reference - and you can write on it!!!) Drive, don't be told how/where to!!! When nav saves your life let us know....just my opinion on nav. Oh, and spare me on the "accident" reporting, that's when the car performs its best, getting out of those man/police made obstacles. Those who navigate out of them using your instinct far outperform those Sunday drivers needy of a way out via nav..

Dec 27, 2008 | 06:58 PM

snagitseven

Super Moderator

Joined: Jul 2001

Posts: 13,980

Likes: 124

From: SE Massachusetts, U.S.

Try screwing around with a map in your lap in Boston if you've never been there before.

I would never be w/o one. I also gave up my old typewriter years ago and now use a computer. And a cel phone, digital camera, television, dvd player, etc. I even got rid of my horse when I bought my first car.