Recently I've had several occasions to drive around in the hilly residential areas here on the SF Bay Area Peninsula. I'm finding the Navigation system gets "lost" quite often. The system will think I am one or two blocks away from where I actually am, and will therefore give bad directions. This only happens on twisty roads in areas where there are lots of trees, so I'm pretty sure it is just a matter of the satellite signal not being strong enough for the receiver. What is strange is that I've had this car since before 2004 and rarely experienced this issue. I am guessing that the recent cloudy weather in the Bay Area is another factor that exacerbated it, but it does feel like the performance of the my GPS system is deteriorating. I never remember it being this bad, where about a third of the time I'm in the hills it is lost. I made sure there's nothing blocking the gps antenna inside the dash behind the MFD. Just curious if anyone else in the Bay Area or elsewhere is experiencing reduced GPS performance recently. At first I wondered if the government had re-enabled the "selective availability" feature that reduces GPS precision, but I don't see anything about that on news searches.
I've had problems in Eastern Kentucky, but that was just the trees and cliffs. I haven't noticed anything in Northern Michigan where we live, so I don't suspect it is an issue with the Global Positioning System. Time of day will make a difference with satellite availability. There is some chance that the number of on line satellites has changed, but I haven't looked into that. Tom
No real location problems in North Texas (Dallas area) - fairly flat topography. The only time my 2004 NAV system has become confused is within underground parking garages and most of its 'dead reckoning' features keep it pretty accurate even then. With my 2007 Touring Pkg 6 ready for delivery tomorrow (Sat Nov 11), I'm anxious to see which DVD version I will have and whether the streets and freeways are substantially updated.
