gps coordinates unreliable

[rollerpen]

I am fairly new, so it maybe something I am doing wrong however, my gps seems very unreliable. When I am on top of a cache and holding the find, my gps may read I am 150 feet away. It never seems to get too close when trying to find the cache

 

I am using a Garmin legend Cx and it does not seem to make a difference if WAAS is on or off. This happens even in clear areas without obstruction.

 

I am not sure if the unit is malfunctioning or if there is something I can do to improve its accuracy.

 

Any thoughts?

[+StarBrand]

First off - check your settings. Make certain the unit is set for WGS84 for the datum and decimal minutes for the format HDDD MM.mmm

 

Second - don't expect the GPS to read 0 feet away on very many caches. The general accuracy of most handheld units is in the range of 15 - 25 feet. Add that to the error that the hider may have had and you could easily find yourself searching for the cache up to 50 foot from where your unit says ground zero is at. Often you find them within 20 feet - but do be prepared to widen your search.

 

Third - transfer caches via the USb and data downloads instead of keying them in to prevent data entry errors.

[Glenn W]

Please note that the antennas on most receivers are directional, and that your body interferes with the signal. Some receivers perform better when held horizontally, some when held vertically; I believe the eTrex units should be held horizontally. All receivers should be held as far from the body as practical, and make sure your hand isn't blocking the antenna.

[rollerpen]

First off - check your settings. Make certain the unit is set for WGS84 for the datum and decimal minutes for the format HDDD MM.mmm

 

Second - don't expect the GPS to read 0 feet away on very many caches. The general accuracy of most handheld units is in the range of 15 - 25 feet. Add that to the error that the hider may have had and you could easily find yourself searching for the cache up to 50 foot from where your unit says ground zero is at. Often you find them within 20 feet - but do be prepared to widen your search.

 

Third - transfer caches via the USb and data downloads instead of keying them in to prevent data entry errors.

 

Thanks for the tips I am already using your suggestions, however I did reconfirm the settings. I don't expect to be led to the point I step on the cache, but it just seemed that 150 feet was a BIG deviation for open area. Numerous caches have resulted in very large errors also.

 

I will keep plugging along.

[+embra]

150 feet *is* a pretty big error, if everything is otherwise right. Are these offsets in the same direction, or do they appear random? Are these happening under optimal reception conditions, or in marginal conditions (e.g., under heavy foliage or among tall buildings)?

 

Edit: Doh! I see you explicitly said in open area. Nevermind on that one.

Edited June 23, 2009 by embra

[+StarBrand]

....Thanks for the tips I am already using your suggestions, however I did reconfirm the settings. I don't expect to be led to the point I step on the cache, but it just seemed that 150 feet was a BIG deviation for open area. Numerous caches have resulted in very large errors also.

 

I will keep plugging along.

Yes - that is a *BIG* error. If you are certain that the data entry is correct and the settings are correct - then I can only assume you have a defective unit. Have you upgraded the units firmware to the latest version?? What screen leads you to believe there is a 150 foot error?

[milmat1]

If i'm having trouble finding the cache I often will just set the GPS down somewhere for a while and let it stabilize for a few minutes.

When I go pick it back up it will sometimes then lead me right to the spot.

 

As someone said, Your error added to the error of the person who placed the cache. As well as if they were in a hurry etc. can lead to tolerance stacking and you could be off a great deal...

[rollerpen]

If i'm having trouble finding the cache I often will just set the GPS down somewhere for a while and let it stabilize for a few minutes.

When I go pick it back up it will sometimes then lead me right to the spot.

 

As someone said, Your error added to the error of the person who placed the cache. As well as if they were in a hurry etc. can lead to tolerance stacking and you could be off a great deal...

 

In response to several questions:

 

1. The distance is listed on the compass screen showing distance when I am right at the cache.

2. The latest update has been downloaded and in the GPS

3. I have not checked for consistancy of distance by moving away in a different direction and coming back. The arrow pointing to the cache seems to be pointing in the right direction and does change as I move around the cache, but the distance is never close.

4. This was purchased as a remanufactured unit, however I have my doubts as to its proper working.

 

Thanks for the input.