[talk-au] Overland Track added

Steve Bennett stevagewp at gmail.com
Mon Feb 22 21:17:41 GMT 2010


On Sun, Feb 21, 2010 at 2:18 PM, John Henderson <snowgum at gmx.com> wrote:
> I suppose it's more popular than when I first walked it - didn't see
> anyone for a couple of days.  A friend did a winter trip around that
> time and didn't encounter anyone else at all.

Yeah, during peak season, there's something like 35 allocated places per day.

> What model GPS have you got?

Garmin Oregon 550.

> The Garmin unit uses an rolling average of GPS-derived altitude to
> dynamically recalibrate.  You then get the best of both worlds.  The
> GPS-derived figure is accurate over a long time in the same position.
> The barometer is very accurate short term, but suffers in the long term
> unless recalibrated.

Ah. What is "GPS-derived altitude" though, exactly - does it rely on a
model of the earth's surface, or is it effectively computing the
distance from the satellites?

Anyway, my recorded elevation for Mt Ossa is 1613m, and the Acropolis
is 1477m. Wikipedia gives Mt Ossa as 1614, and the Acropolis as 1481m.
Maybe this method is more accurate than I was expecting...

OTOH, I'm still not convinced that all this is necessary. Surely using
figures from an authoritative source would serve everyone a lot
better...

Steve




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