Hi there,

Recently we were driving through the Pyrenees, which was our first real experience of driving through the mountains whilst using GPS. Anyhow, we found that all the way through the GPS had us in a completely different position than we were (the sea!). I presume that this is due to the GS signal bouncing off the mountains. But I am no expert.

The GPS we were using was a cheap 2nd hand one picked up from eBay, and I dont know whether the GPS mouse was any cop. What I was curious about is whether this is something that should be expected, or perhaps a more expensive GPS receiver would not suffer this issue.

Thanks

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Ollie

www.jollyfollies.com

Land's End to Sydney 2009

Ollie.
What brand and Model is your GPS?
Have you tryed to make a cold start (Start the GPS and tallig him to auto-locate).
Regards,
Ramon

Assume you had correct map datum etc. programmed in?

Matt

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http://scotlandnepal.blogspot.com/

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I experienced the same thing in the Alps with my TomTom Rider 1... which has the latest chipset (SirfStar III). The signal bounces off the mountain, and gives echos, which confuses the timing, and generally offsets you in one direction. Clears up once the mountain slope decreases.

Same thing happens in cities - large tall buildings ...

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Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S

Yes, the GPS was working fine for 1000s of miles, jsut not in the Pyrenees. looks like it is a common problem. Got a new one coming anyhow ...... couldn't stop myself

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Ollie

www.jollyfollies.com

Land's End to Sydney 2009

It's not a problem, just a bit inconvient
If you read the manual, you'll find your device somehow has to 'see' the satellites. The more satellites it sees the more exact it nows where on the globe it is/you are. Based on the positions of the different satelites it calculates its position and height, as soon as one or more sats are blocked, permanent (behind the horizon) or temporarly (buildings, trees) the calculations get less exact. When signals get bounced and deflected things can get even more difficult to calculate.
Because of all this satellite detection and calculations it can take long (up to 20 minutes) when you first start your GPS after a long time and/or a big transition, it litarly get's lost (most systems you can help, give it a new initation).

A car, by nature, is a bad surrounding because all it's metal can block but even worse, it can deflect the satellite signals, giving false readings. If you find this happening, an external antenna outside the vehicle can help you, given it has a clear view at the sky.

I wouldn't be very worried about it, if you constantly have one eye on your device, you'll notice this glitches (and get worried), they are mostly short, and most of the time there is only one route/road/track to follow. Look outside, enjoy, use this one eye to glance on your clocks/gauges/warning-lights ánd GPS every now and then.

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bart & sophie