Re: GPS Accuracy
R. Locke (rfl@OFFPRO.NET)
Wed, 15 Jul 1998 10:52:04 -0400
Chuck May wrote:
> Can anyone tell me what the positional accuracy of hand-held GPS receivers
> (the kind suitable for hiking) is (+/- 10 meters, 100 meters, etc) for
> finding features on a standard topo?
> Also, are they available for short term rental anywhere?
Theoretical accuracy (x,y coordinates) is on the order of 3 meters or
less. Due to Selected Availability (SA), a system of random errors
induced into the positioning system by the Department of Defense, the
stated accuracy is something like "accurate within a 100 meter CEP, 95%
of the time."
In the real world, the answer is *VERY* accurate, more so than you
will ever need to navigate by topo map. The best source on the 'net for
GPS information is the newsgroup sci.geo.satellite-nav.
I'm not aware of any short term rentals of consumer grade GPS's since
they cost as little as $99 sometimes less. Check out www.onsale.com.
Do a little research before plunking down any money for a GPS. I think
the minimum would be a Garmin or Magellan unit with a 12 channel
*parallel* receiver, that can display in UTM coordinates.
Terry Howerton Sakima Group, Inc. SCOUTER Magazine Kansas City