Archaeolgy work requires better accuarcy than 10m. If you are leaving
finds in situ (as we were) to study long term erosion and to return
for photography (my role) then 10m is not much good.
Sent from my iPhone
On 28/12/2009, at 5:02, Peter Shute <> wrote:
Regarding GPS accuracy, my phone generally claims the coordinates
are within 10m, sometimes much lower, occasionally higher. I would
imagine that's easily good enough for finding most birding locations
again, what kind of accuracy are you talking about?
I'm under the impression satellite signals are deliberately encoded
to prevent civilians getting too much better accuracy than that, for
military reasons, including making it hard to pinpoint the location
of the actual satellites in order to shoot them down. To get better
accuracy (precision might be a better word), I think a long
succession of coordinates must be averaged. This may be what the
more expensive gear does.
Not so very long ago, GPS wasn't even an option. The alternative for
those without access to expensive electronic distance measuring
equipment was a tape measure or triangulation. In my opinion, the
decision by the USA to release even this level of accuracy to
civilians is absolutely wonderful, even if it does occasionally lead
you back to the wrong side of the creek.
Peter Shute
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Sent using BlackBerry
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