PDA

View Full Version : Navigation Observation


jadnashuanh
01-08-2012, 01:26 PM
I've got the HUD, and did the European delivery this past April 2011. While there, the arrow indicating the road direction (it shows curves, etc. while driving) was right-on - as you entered a turn, it showed the direction and relative circumference of that turn. When using the nav, distances to turns were quite accurate.

When I got the vehicle back to the states, neither of these indications are anywhere near as accurate. It will announce a turn sometimes long after you've gone around the curve, and distance to the next turn initially seems off by as much as 400' or so. On a recent trip to the UP of Michigan, I was driving on some back roads that were not in the map database. When I turned onto a road that was included, for about 1/2-mile, it showed me paralleling the road until the 'keep on road' logic popped the vehicle sideways to the road. this tells me several things: the maps and the gps are not programmed to the same systems, and they need to work on their 'keep on road' logic.

I recently sent BMW USA customer service a note. They are communicating this to the techs at corporate in Germany. If I'm right, there is probably an easy s/w fix.

FWIW, since the earth is not a perfect sphere, mapmakers have come up with numerous reference systems and models to make 'local' maps more accurate. They do this with defining spheorids and datums. The GPS logic must be programmed to match the maps supplied, and this can differ based on who did it (in this case it is the same supplier that does the maps for Europe and the USA), and, probably more important, for the spheroid and datum used. In the USA, there are at least several datums that are commonly used: NAD27 and WGS84 being the more common ones. While WGS84 is more of a 'global' datum and spheroid, it may not be as accurate locally as those specific to one area. European maps tend to not use either NAD27 or WGS84. My guess is that the maps supplied for the NA vehicles and the datum/spheroid they are drawn in, is not being programmed into the GPS, and this is causing the errors I and others have reported.

Anyway, hopefully, I'll hear something in the next few weeks, and if my observation is correct, it should be an easy s/w bug to fix. Now, when we may see it is another thing.

now, if the map updates were more reasonably priced, things would be even better!

zeeway
01-08-2012, 01:59 PM
I have been impressed how accurate the nav is - when I am passing under/over a crossing road, the nav system shows it exactly. My system accurately announces roads better than the nav system in our 2010 CTS. I have found some roads missing, but not very many.

Angie

jadnashuanh
01-08-2012, 04:43 PM
Maybe it's an issue with vehicles delivered in Europe for eventual redelivery in the states. But, I've heard from more than one person who has the same issue as I do. It could be that the installation of the USA maps at the service center is missing a reprogramming step.

Mikez38
01-09-2012, 10:22 AM
I have been impressed how accurate the nav is - when I am passing under/over a crossing road, the nav system shows it exactly. My system accurately announces roads better than the nav system in our 2010 CTS. I have found some roads missing, but not very many.

Angie

Does it announce names of the road of just when to make a turn.
I wish the nav sys would show the name of the road currently being driven on. Most navs do so.

zeeway
01-09-2012, 10:24 AM
It announces just the ones onto which you are turning. And you are right, it does not show the name of the road you are on, if you are on guidance. Sounds a little strange, but you can show the name of that road, by stopping guidance.

Angie