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In general I can't complain...retrofit of US unit was painless and almost everything is working fine. ALMOST ;)

I park in downtown skyscraper, concrete etc. Evry day when I'm coming out of the parking my XM or NAV acts weird. XM is "UPDATING LIST" and usually last remembered station is lost so it takes 10-30 sec to get the signal.

NAV is not calibrated properly...that means you are on the street facing north but NAV is showing you off the street facing for ex. NE. Takes about 2-5 min before system is calibrating again and everything is back to normal.

Now from what I suspect...all those problems are caused by me parking in solid concrete garage so when I enter garage facing South (last NAV entry) and then exiting garage facing North (first NAV entry after signal is lost) unit is getting "confused" and starts recalibrating. That never happens when I park on open parking or street.

Just wonder if any of you with E unit experienced something like that?
 

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PROXUS said:
I park in downtown skyscraper, concrete etc.

NAV is not calibrated properly...that means you are on the street facing north but NAV is showing you off the street facing for ex. NE. Takes about 2-5 min before system is calibrating again and everything is back to normal.
That's normal operation for any GPS system.

After several hours parked the satellites have moved (they're not geo-stationary like the ones for TV) so it takes a while for the GPS receiver to detect them again. Because you're in what's called an "urban canyon" (downtown skyscrapers) the GPS signals are very weak so it takes even longer to detect the satellites again.

The car park exit being in a different place and your heading being different just makes it take even longer.

Even the very newest GPS receivers have this problem - it's something we'll all just have to live with. If the bult-in gyro was better it would reduce the time to get a GPS fix - certainly my gyro tells me I've turned about 110 degrees at a 90 degree corner.
 

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Discussion Starter #3
That makes sense, especialy in downtown (20+ floors buildings) I got 2-3 satellites at the most
 

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i have a similar problem ("C" unit though).. the entrance to my garage is pretty long and parallel to major street (offset by ~50meters) and also a bit of an urban canyon.. everytime i pull in my driveway, it snaps to the major street nearby.. obviously when i pull out of my driveway it is all messed up..

it seems to figure everything out after a few minutes..
 
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