Garmin question

Why is my GPS recording incorrectly?

Walking with friend yesterday...we both have same model Garmin = 60CSx - at
end of walk my track mileage showed 12+ miles - his 10+ miles!..I'm assuming
friend's record is correct and mine incorrect.
Clue is in the recorded tracks as downloaded onto Memory-Map...see
below...green line is my track, red is friend's track....as can be seen my
green track goes bonkers from time to time:-

Example 1 - Walking beside river, heavy tree cover, after dark
...note green track zooms off across river whereas we walked along the left
hand side of the river..even red track shows incorrectly located into the
river at one point:-
http://tinyurl.com/3xse24

Example 2 - Crossing swollen streams in steep sided valley, plenty of tree
cover
...note variation of tracks:-
http://tinyurl.com/33jmw4

Example 3 - No tree cover, open rural countryside
...note tracks together for about half mile before and half a mile after 10
minutes spent inside and around an old church...where green track goes all
chaotic:-
http://tinyurl.com/2qe4s9

The other thing to mention is my Garmin was generally located in trouser
pocket during the walk...friends in his jacket pocket at chest level...
...but why would this cause the zig zagging and thus the extra mileage?
And finally...on way to the start of the walk...some 25 miles from home,
both Garmins recorded the exact same distance (and equal to the car
mileometer)..when both located on car dashboard.
I'm assuming the problem lies in my Garmin having more difficulty in
locating satellites? (although the sales info shows: With the GPSMAP 60CSx,
you can find your way in almost any conditions:High-sensitivity GPS receiver
gives you improved satellite reception even in heavy tree cover or deep
canyons ...although sure it doesn't mention its ok to carry it in trouser
pockets!)
Any constructive thoughts. Thanks, John

On Sat, 19 Jan 2008 16:21:30 -0000, "John Brown"


It's to do with signal quality. When it doesn't have plenty of sats
to get info from it guesses so instead of walking in a straight line
it thinkgs you're zooming left, right, up that hill, over there, up
here. The shortest route would, of course, be a straight line.
--
-- Nick ICQ: 9235201 EMAIL & MSN: nickmooney@spamcop.net
-- Triumph Tiger 955i -- http://www.bgn.me.uk -- Touch -
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Cheers - thanks for comments..need to get a gps holder :-)
J
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The MAPman series have a setting that tells the device how often to take
log points. You can set it to take log points at regular time intervals,
or at regular distance intervals, or a combination of the two. Check the
setting on yours and your friend's devices and see if they're set the same.

I would guess (but I've no practise at this) that your friend's device was
set to take points at regular time intervals, but yours was set to take
them at regular distance intervals.

Simon.
--
http://www.hearsay.demon.co.uk

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God point Simon, thanks - I'll check that out.
J
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