[Tagging] Topographic Prominence for Peaks

[Graeme Fitzpatrick]

On Mon, 24 Sep 2018 at 16:06, Joseph Eisenberg <joseph.eisenberg at gmail.com>
wrote:

>
> That’s why we need to check the height of saddles and peaks “by hand”, or
> better yet by survey with GPS.
>

Joseph, just a technical question, thanks, as I don't understand *any* of
the details of what you're wanting to do! :-)

How do you determine the height of the saddle / peak?

Do you sit there & say that that mountain peak is shown on my map as 4500m
& I'm about 300m down, so this saddle is 4200m?

& when you say survey with GPS, is that accurate enough for an altitude
reading? With my Garmin GPS (which admittedly is 10 - 15 years old, but
*wasn't* a cheap one!), I can calibrate it in the back yard at 6m ASL, go
for a day trip & when I get home, it displays the exact same spot as
anything between -5 & +30m ASL :-( When out driving, I've also seen the
altitude display change by 100s of m's instantly, when the road is
virtually flat.

Thanks

Graeme
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