Iain,

Your GPS choice largely depends on your need for accuracy.  With SA turned down,
the more affordable handheld units will give you two-dimensional point accuracy
of *around* 50m, and somewhat worse for elevation.  This figure is not so much a
result of SA but inherent imperfections in the electronics of the units-- you
are getting what you pay for after all.  But US$200 for a handheld box that can
find you anywhere on the planet with 50m or so is pretty good!  Still, with SA
off, the accuracy of any uncorrected GPS unit will improve by around 50m (from
100m), perhaps even more depending on the unit and the number of satellites it
can see-- I've heard of people getting 10m accuracy consistently (I know the GPS
manufacturers are saying this), but I haven't seen it myself.  In reality, I
should think that people are getting 20m - 40m accuracy with their handhelds on
a day-to-day basis.  (Does that sound right, folks?)

In any event, if you're just using a GPS unit to navigate and record transects,
and are convinced you're not going to need submeter accuracy, any of the
handhelds people have mentioned so far (a Garmin 48 and a Garmin Etrex, I think)
would probably be just fine for your purposes-- epsecially if you're working in
the open and not under a leaf canopy.   I personally like Magellan, but that's
more personal preference than anything.  If you do need submeter accuracy, you
can probably manage it without buying into Trimble-- I suggest contacting a
local GPS person and going from there.

Hope this helps.

Best,
Jason Menard
-----------
Jason Menard
Department of Anthropology
239 Appleby Hall
University of Minnesota, Twin Cities
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Iain Stuart wrote:

> I would be interested in finding out what GPS receivers archaeologists are
> using in this post-selective availability era.
>
> I have some experience with Trimble units but these seem terribly expensive
> for what they offer and I was wondering whether there are other alternatives
> around.
>
> The primary use for a GPS would in my case be in locating sites and
> producing accurate AMG grid references and possibly tracking survey
> transects.
>
> Iain Stuart
> Principal, Archaeology and Heritage Management
> HLA-Envirosciences Pty. Ltd.