Re: [Paddlewise] Garmin eTrex GPS

They are not going to line up.  Right now a "fuzziness" is deliberately
introduced into the GPS position which produces a 200/300 yard ambiguity.
The ultimate accuracy will be about 25 feet when the totally clean signal is
available.

I would like to point out that the present accuracy of the signal is more
then adequate for navigation.

Richard Smith
----- Original Message -----
From: <dmccarty_at_us.ibm.com>
To: <paddlewise_at_lists.intelenet.net>
Sent: Tuesday, April 04, 2000 9:53 AM
Subject: RE: [Paddlewise] Garmin eTrex GPS


> |But do I need the map capability?
>
> Hmmmmm, good question.  But how good are their maps?
>
> I don't have the answer to the last question but my experience with both
> topomaps and lake maps is that they can be very  inaccurate.  If the GPS
is
> accurate but the maps are off what is the point?  I have used my 12XL to
> try to pinpoint locations on topomaps and have been greatly suprised how
> inaccurate the maps seem to be.  A few years ago I was trying to locate
> property boundries on a topo map and it seemed to be really inaccurate.  I
> could find major landmarks on the map and I had multiple readings from the
> GPS but did not have confidence on putting points on the map.
>
> I wrote the previous paragraph last night but held off posting because I
> had taken about a dozen positions on some property this weekend.    So
last
> night I tried to plot the positions on a 1:24000 topo map and the map is
> off anywhere from 200-300 meters both north to south and east to west.
> This is similar to what I seen on another topomap a few years ago.  I'm
> very familiar with the topography of the land, and I can very easily guess
> property boundries from ground features.  But the map features and the GPS
> positions don't line up.  Since I was walking in straight lines along a
> marked survey line I have confidence that the GPS numbers are accurate.
> They certainly are consistent.  Soooo, either the map is wrong or I can
not
> plot points on a map........  8-)
>
> On the other hand do you really need accuracy down to the meter?  These
are
> not nautical charts either which may be more important to you than a topo
> map.  Hopefully nautical charts are more accurate.....
>
> Hope this helps...
> Dan
>
>
>
>
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