[OSM-talk] Garmin eTrex Vista Hcx

[Mike N.]

> 3. I parked my car near a village a day before, marked a waypoint.
> The satellite error was at +- 5metres. Today morning, I came back
> and marked another waypoint. This time the error was +-4 metres
> but this waypoint is 150 metres off the earlier one. The car keys
>were with me and I can vouch that my car does not move on its own. :)

  I haven't tried to calibrate elevation, assuming the GPS altitude has a 
large error.   But I would have expected the altimeter correction to return 
to the same altitude after returning to the start point.   I actually see a 
20-50 Meter error after a route of only a few hours.   I doubt that the 
barometric pressure had changed so much during my trip.