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

[ael]

ael wrote:
> 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.

Correction: the manual is "UsingaGarminGPSwithPaperLandMaps_Manual.pdf"
rather than the Beginner's manual.

ael