Incorrect recording Garmin?

pjcactus · Occasional Visitor Joined: Jan 26, 2008 Posts: 30

I have a GPSmap 60CSx...
V. pleased with it except starting to wonder if it's measuring tracks incorrectly?
The other day went for walk with a mate who has identical model...at the end of the walk his showed we had covered 10+ miles whereas mine recorded 12+ miles. Only difference we could think of - His Garmin was carried in coat pocket - mine in trouser pocket where can imagine more difficult satelite reception.
Clue is in the recorded tracks as downloaded onto Memory-Map...see
below...green line is my track, red is mate'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

So thought I'd try this...
At the end of another walk kept GPS switched on and placed it on house kitchen surface near window.
During the 4 hours when it physically wasn't moved the track length increased by 1.50 miles with extreme zig zag display display!
And further, later, located the machine outside in the centre of the lawn with very clear overhead conditions and found the track length increased by 0.18 miles during 2 hours.
Any constructive thoughts/comments?
Thanks.

M8TJT · Posted: Sun Jan 27, 2008 3:29 pm Post subject:

missing_user · Joined: Aug 30, 2008 Posts: -7

The unit is very sensitive and picks up signals where others do not, as a result it continues to record and move about while in the house!
Using Mapsource you remove the actual preparation for your walk and end it at the end of the walk - not in the house!

Have you set it to 'off road'?

What setting for the frequency of recording of the tracks have you set it for?

Do you use the full track from within the SD card [10,000 points]rather than the track you see normally which has a limit of 500 points?

I have Garmin topo and it would be interesting to see how your full track [SD card] looks on that!

mikealder · Posted: Sun Jan 27, 2008 3:31 pm Post subject:

I would say your GPS signal is either being lost or degraded creating all the rubbish on your tracks, this rubbish is adding to the total distance giving a false reading, hiding the unit under extra layers of clothing isn't a good idea to start with.

If you can still get hold of your mates receiver I would compare some settings to make sure they are both set-up the same way, look in Tracks/ Setup and ensure Record Method and Interval are the same, also check the WAAS/ EGNOS state.
Once you are sure the devices are setup the same try it again on a walk, you will get a difference in distance but it shouldn't be anything like you have experienced. - Mike

missing_user · Joined: Aug 30, 2008 Posts: -7

This is slow walk [at my age] along the treelined narrow rural road.
Setting 'Lock to road-OFF'.
The track is from the SD card in both directions:-
312 points in 29 minutes' so the 500 saved track limit would 'filter' a longer walk if saved in the unit not the SD!

I think the result at Zoom 200ft is very good for the track in both direction along the road which is shown, and for following the 'rule of the road - facing the oncoming vehicles!! Very Happy

The tracks in both directions were up to a max. of 25feet apart [allowing for a 10 feet width of road and different sides of the road on the return] quite a pleasing result.

M8TJT · Posted: Sun Jan 27, 2008 4:06 pm Post subject:

missing_user · Joined: Aug 30, 2008 Posts: -7

How did you guess? Embarassed

Next time I must ask the navigator to carry the GPS.

M8TJT · Posted: Sun Jan 27, 2008 4:16 pm Post subject:

Perhaps carrying both you and the GPS would be a better idea. Very Happy

OOps going off topic Embarassed

. Must stop doing that. Sorry, (but couldn't resist it)

missing_user · Joined: Aug 30, 2008 Posts: -7

I left my 60csx on in my office [no direct windows - no rooms above me - but there was a concrete tile roof] 75 minutes - travelled 380 feet on a 27 feet radius!

Lock to Road OFF on the left
Lock to Road ON! on the right added later!

.

..

.
.
And no my GPS does not drink!

Darren · Posted: Sun Jan 27, 2008 6:46 pm Post subject:

One other thought, are the two units identical? ISTR that Garmin changed the chipset at some point in those models?
_________________
Darren Griffin

missing_user · Joined: Aug 30, 2008 Posts: -7

Lock to Road ON
The radius is now 137 feet as it is trying to lock onto roads both sides of the house!

pjcactus · Occasional Visitor Joined: Jan 26, 2008 Posts: 30

pjcactus · Occasional Visitor Joined: Jan 26, 2008 Posts: 30

Darren · Posted: Sun Jan 27, 2008 10:57 pm Post subject:

pjcactus I've corrected the quoting in your replies above for you but for future reference you need to 'close' any quotes you make to ensure the replies read correctly Smile

_________________
Darren Griffin

pjcactus · Occasional Visitor Joined: Jan 26, 2008 Posts: 30

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