[OSM-newbies] Altitude/elevation with OSM and Josm

[ael]

Harald Kirsch wrote:
> 
> Am 05.01.2008 10:02 schrieb Mark Williams:
>> Harald Kirsch wrote:
>>> Am 04.01.2008 23:31 schrieb Mark Williams:
> 
>>> Ok, thanks. Which brings me right to the next question. Is there a way
>>> to convince JOSM to show altitute values form imported GPX tracks?
> 
>> It would be nice to have a plugin that looked for, say, the nearest 10 
>> points & took a weighted average altitude - but you then have issues 
>> around calibration (my Garmin can easily be 40metres out if the weather 
>> changes). I'd love something you could activate for a session, which did 
>> this for new nodes.
> 
> This sounds like you have a barometer in your GPS, which I have not.
> Nevertheless I get altitudes, and I would have thought they are not far
> more off than the plane-coordinates, because GPS is "just"
> triangulation. But from what you say I assume that the altitude
> measurement provided by triangulation is even worse than the 40 metres
> off. Is that true?

Page 40 of the Garmin "GPSGuideforBeginners_Manual.pdf" (available on
their website) has a section:
"Satellite Geometry, and why your horizontal location is reported
more accurately by your GPS than your elevation (vertical location)"
which covers the issue.

ael