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GPS off by 16 miles?


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I made my first attempt today. I picked a very local cache, especially since I had the clan (5 year old, 3 year old, 6 month old). I have a Garmin eTrex, and upgraded the software to version 2.14. I used EasyGPS to load coordianates and route from the web site. I know I started within a few hundred feeet of the starting point (school parking lot). The GPS kept indicating I was around 16 miles away, but given that the area was relatively small, that couldn't be accurate. Any ideas on why I was so far off?


My 3 year old was quite upset we couldn't find the treasure, and I promised him we'd go again next weekend. Any help is appreciated.

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The 4 most obviouse things to check. No insults intended. In no particular order.


1) Are you sure you started in the right schools parking lot?


2) Did you enter the coordinates wrong?


3) Has this cache been found before (so you know the hider put in the right coordinates)


4) Did the hider indicated the right school in the description (or send you on to the wrong schools parking lot?)



Wherever you go there you are.

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A few other things to check:


Is your datum set to wgs84? This generally will not result in a really large error, but definitely enough to make finding a cache difficult if not impossible.


Is your coordinate system set to DDD MMM.MMM (degrees, minutes, and decimal degrees) This is the correct seting.

Other possible alternatives are DDD MM SS.SSS (degrees, minutes, seconds) or DDD.DDDDDD (degrees and decimal degrees)- this is a very likely possibility because it would result in a great deal of error, either of these wrong settings will cause your readings to be off.


After checking these settings, I would suggest trying another local area cache, perhaps even one hidden by a different player.


Also it is possible to have occasional anomolies with that much error or more(I have had anomolies over a hundred miles off on occasions).


These anomolies usually only last a very short time, but sometimes when I have experienced them with my Garmin Street Pilot, it has detected errors and required me to power down and restart. In a few cases, it did not warn me and I had to restart to correct the errors.


These anomolies are somewhat rare, but have occurred to me several times over the past several years- usually in the same general area.


Might try restarting GPSr and check batteries.

Caint never did nothing.

GDAE, Dave

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It sounds to me as if you used the wrong geodetic datum. If you have incorrect conversion, such distance discreepancies are possible.


I know, because I spent 2 hours in a snowstorm at 11:00 at night looking for a cache in someones cow pasture. I later laughed, but was most displeased at the time.


The coordinates you take from the geocache website are wgs 84. If your gps is set to use nad27, that would cause the problem. Or when you input the coords, your software could have its setiingss to the nad27. Hope this points you in the right direction. Post if you need more help, or email me.


Two roads diverged in the woods and I,

I took the one less traveled,

and that is how I found the cache.

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Thanks for all of the quick responses. Location was right because there is only one school with that name. The other appealling factor was that someone in the notes said the coordinates were very accurate.


I've checked settings on GPS:

Datum: WGS 84

Position Frmt: hddd mm.mmm (this seems closest to what was specified)


I downloaded the coordinates directly from the website into EasyGPS. I'm using the default settings in EasyGPS, but I'll see if that's wheer the issue is.


Otherwise, I'll try another local cache.


Is there a way to reset the eTrex?

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You might post the cache that you are trying to find so some of the gurus here can see where it shows up on their software maps.


Also try putting the coordinates into LostOutdoors.com and see where it says it is. You can almost geocache based on the Topo and Photo maps without a GPS from that site.

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16 miles icon_eek.gif is certainly not Datum (or really format) related. Really to be consistently off by 16 miles sort of tends to indicate the coordinates have an issue or you simply weren't where you thought you were or supposed to be.


Cheers, Kerry.


I never get lost icon_smile.gif everybody keeps telling me where to go icon_wink.gif

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I think it is most likely user error on my part. I'm going to pour through the manual again, and then also try another cache that's only a mile or so from my house.


I'm pretty sure it was 16 miles, because I could zoom down on the Tracks view to a much smaller area. The waypoints were only visible when I was in 20m view.


I really appreciate everyone's help. What a great community. Once I get his figured out, I'll post where I went wrong.

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Check the unit against a known location.


Retry the same coordinates again. Localized anomalies do pop up occasionally, but as earlier mentioned, tend to be short-lived. If it was a permanent anomaly the original coordinates would be off also.


Then start with the settings again. Check the distance units, datum, coordinates for switched digits. Reload the upgraded software again.


After that, contact tech support from the web site.



"The time has come" the Walrus said "to speak of many things; of shoes and ships and sealing wax, of cabbages and Kings".

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