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Thread: GPS Errors

  1. #1

    Join Date
    Mar 2010
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    Default GPS Errors

    I am beginning to get a bit annoyed with my Etrex Leg-end HCx. We had some trouble when on hols in Wales with Beauchief. Every cache we approached their GPS was much more accurate than ours (they have the base model "yellow" Garmin) ours was, several times about 100 feet out, Now we have started out with our own hides we have had several cachers comment that the location co-ords seemed a bit out ! I have read all the advice. Checked and re-checked but still get a mean average of about 20/30 feet out. Which, as we concentrated on "Drive bys" for our first series can put the location on the opposite side of the road !!
    This wretched situation gets worse when I go caching on my own. For instance I went out last weekend to do a really great new series called Prize Norton. No one else about - result 3 FTFs and 3 DNFs. The GPS gave location but took at least 20 mins scratting about and the 3 DNFs were easily found by the next cachers along. It gets a bit dispiriting as the damn thing tells me I'm right on top of the cache and even with the fingertip search I am having trouble. This is happening too often to be put down to a "bad day" - Anyone any advice to improve accuracy ? If not I will sell the Etrex and try something else ???
    Si vis pacem para bellum

  2. #2

    Join Date
    Oct 2005
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    Land of the Bear and Ragged Staff!
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    Default

    Got the unit set to the correct Datum?
    (That can lead to around 50ft out)
    I have a Geocaching problem...
    Work gets in the way!

    * Cache Walker -Caching by byway, not highway! CacheWalker.co.uk
    Walking and Caching in Warwickshire, Worcestershire, Gloucestershire areas

  3. #3

    Join Date
    Oct 2005
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    Land of the Bear and Ragged Staff!
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    Default

    Or are you looking for a response like

    "It's broken. Time to get a new one."
    I have a Geocaching problem...
    Work gets in the way!

    * Cache Walker -Caching by byway, not highway! CacheWalker.co.uk
    Walking and Caching in Warwickshire, Worcestershire, Gloucestershire areas

  4. #4

    Join Date
    Oct 2008
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    Default

    Must admit that I had a Legend HCx and couldnt fault it, often had an accuracy of +/- 10ft and would always take us to within 10 to 15ft and when I set cache locations with it finders used to comment on the closeness of the co-ords.

  5. #5

    Join Date
    Jan 2006
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    S. E. Wales
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    Default

    Quote Originally Posted by Bear and Ragged View Post
    Got the unit set to the correct Datum?
    (That can lead to around 50ft out)

    As above...

    Are you set to Degrees and decimal minutes (HDDD° MM.MMM) with WGS84?


    ...Otherwise, don't expect your GPS to be 'spot on' accurate, within 20ft is acceptable accuracy - and if you're looking for a cache and the hider's GPS is also "within 20ft accuracy" it's quite possible that the cache could be within a 40ft radius.

  6. #6

    Join Date
    May 2004
    Location
    South East Wales
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    Default

    Another thing with the eTrex series. The aerial is the 1 inch square silvery thing you can see just under the plastic above the screen. You need to hold the unit flat in your hand with the screen facing up for best reception. If you've got it on a lanyard hanging round your neck you'll find you won't get such a good signal.
    Also, take a look at the satellite display screen. It's not uncommon on some days to have no satellites directly overhead but several on the 45 degree line. If you view to the horizon is obscured by hills or trees that again can reduce the signal quite substantially. Have a look here for a screen shot of what I'm referring to.


    Chris
    Graculus
    Volunteer UK Reviewer for geocaching.com
    UK Geocaching Information & Resources website www.follow-the-arrow.co.uk
    Geocaching.com Knowledge Books

  7. #7

    Join Date
    Mar 2010
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    Default

    Quote Originally Posted by Bear and Ragged View Post
    Or are you looking for a response like

    "It's broken. Time to get a new one."
    Not really its only about 3 months old but thanks for all the useful replies I will check out in the morning when I get home from work
    thanks again
    Si vis pacem para bellum

  8. #8

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    Default

    Quote Originally Posted by Mrs Blorenge View Post
    As above...

    Are you set to Degrees and decimal minutes (HDDD° MM.MMM) with WGS84?


    ...Otherwise, don't expect your GPS to be 'spot on' accurate, within 20ft is acceptable accuracy - and if you're looking for a cache and the hider's GPS is also "within 20ft accuracy" it's quite possible that the cache could be within a 40ft radius.
    Thanks I will check it out in morning when I get home from work
    Si vis pacem para bellum

  9. #9

    Join Date
    Mar 2010
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    Default

    Quote Originally Posted by Mr Blorenge View Post
    Another thing with the eTrex series. The aerial is the 1 inch square silvery thing you can see just under the plastic above the screen. You need to hold the unit flat in your hand with the screen facing up for best reception. If you've got it on a lanyard hanging round your neck you'll find you won't get such a good signal.
    Also, take a look at the satellite display screen. It's not uncommon on some days to have no satellites directly overhead but several on the 45 degree line. If you view to the horizon is obscured by hills or trees that again can reduce the signal quite substantially. Have a look here for a screen shot of what I'm referring to.


    Chris
    Graculus
    Volunteer UK Reviewer for geocaching.com
    UK Geocaching Information & Resources website www.follow-the-arrow.co.uk
    Geocaching.com Knowledge Books
    I remembered the bit about it being flat from you hints on ensuring you have the correct co-ordinates when putting out caches. I lay it flat on wall and leave it to settle for 5 mins or so before clicking on the waypoint marker - so I think that's ok - I have, however to look at the other bits pointed out on the replies (i.e. datum etc) before committing ceremonial Hara Kiri !!
    thanks again for all your help
    Si vis pacem para bellum

  10. #10

    Join Date
    Nov 2009
    Location
    Shropshire
    Posts
    563

    Default

    I find my Legend is not quite as accurate as my Nuvi, although mostly it gets me within 20 feet and sometimes is bang on.

    But I too have friends with units that seem to get them right on top of the cache every time - a couple of yellow Etrex H, and an Oregon.

    I think it's just pot luck though.

    I use the nuvi when setting caches and quite a few finders have said how good the co-ords are.

  11. #11
    pronky Guest

    Default

    hi me to faced the problem brilliants guide me

  12. #12

    Join Date
    Jun 2005
    Location
    Cambridge
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    Default

    I've got an Oregon and even that sometimes gives me a dodgy reading or two.
    I notice it more when out with others caching - but it seems to happen to everyone from time to time when your GPS is the only one to point in a different direction to the others.

    It can be quite comical sometimes when all 4or 5 GPS units point in different directions.

    Sometimes I find it more of a problem when the batteries are reaching the end of their charge.

    Doesn't stop me caching though :socool:
    Happy Caching

    Gazooks

    - Setting a good example for children takes all the fun out of middle age.

  13. #13

    Join Date
    Aug 2010
    Posts
    19

    Default The e-trex yellow brick

    I started geocaching about a month ago and bought an e-trex H which I think is the cheapest receiver in the range. On a number (most) of the caches I discovered I found the coords to be about 4 or 5 meters out. The closest I have got to a cache is about 1 meter and I think that is just a coincidence. If I mark a spot in my back garden and then walk 20 meters away and try to use the GPSr to get back to the spot it is usually 1 to 2 meters out. If I stand stationary and mark the spot a number of times then the coordinates vary by 0'001 to 0'002. I am not sure what 0'002 is when converted to meters. I think therefor that to expect your gpsr to take you exactly to the spot is asking too much and you should be quite happy to get to within 4 meters of the site.

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