[pct-l] GPS class

[William Canavan]

Dennis,
GPS is actually very precise.  A common mistake made using a GPS unit is
not setting the map datum in the GPS unit to the datum of the map you are
using.  That could mean an error of hundreds of yards.  If you are in a
group (class) and you are "all over the place" I would bet that what
happened is several units were set incorrectly.  So even if you all
manually entered the same coordinates you could be a ways apart.  I haven't
counted but there could be 20-30 datum to chose from just in North America.
Enjoy your hike!
Little Brown

Message: 38
Date: Mon, 11 Mar 2013 16:01:02 -0700
From: Dennis Phelan <dennis.phelan at gmail.com>
Subject: Re: [pct-l] navigation without GPS
To: "pct-l at backcountry.net" <pct-l at backcountry.net>
Message-ID:
        <CAE1UnwS3+-VxydwEQ7HZ1YG_v8LaRWPVGyvW-wBomORjnS3X4g at mail.gmail.com>
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I took a GPS class from REI (tualatin oregon store) that was fantastic.  We
meet in a local large forest park that had trails.  We learned how use a
GPS waypoints to find points in the park.  We then created a waypoint from
a map based on our calculations and then in teams used our GPS to go to
that waypoint.  What was really interesting was to see how imprecise GPS
are.  We were all over the place even though our GPS's told us we were all
in the same spot.  Maybe the GPS class I attended was unusually good, but I
have done other REI classes and I find them to be pretty good.

Dennis