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28 November 2009 @ 04:11 pm
Just a *tad* off target...  
Does anybody know how to increase the accuracy of a Garmin eTrax Legend CX? I was out Geocaching today... and twice, my GPS had me off target. I found out I was off target when another Geocacher showed up looking for the same ones and she found it before me and when I was not standing close to it. The husband mentioned about getting my GPS reconfigured so it would be more accurate. I tried for a third one which took me onto a main highway bridge. Even though the description said that "I can reach it from the Pedestrian walkway easily", my GPS wanted me to stand in the middle of the road. O.o

What can I do to increase the accuracy? Or is this another learning curve I need to go through?
 
 
Current Mood: confusedconfused
 
 
 
Rickhrrunka on November 28th, 2009 10:11 pm (UTC)
I guess it depends a bit how much you mean by 'a *tad*' ;)

If you've got WAAS enabled and you've been getting a good WAAS signal then accuracy should be excellent, but it can take a while for some units to get enough WAAS information to fix things well. I've seen units give rather variable results when WAAS was not yet up to speed.

Of course, if you're somewhere where WAAS doesn't do the business then you're back into the "plus or minus twenty or thirty feet" ballpark that was the going accuracy when geocaching started...

Then, of course, there are all the other usual factors. How many satellites are visible. How well spread are they. Is anything bouncing signal from any of them. What's the tree cover like. Etc...
Wildfox: lazyfoxwildfox34 on November 28th, 2009 11:04 pm (UTC)
Well, I was in a local park for the Skate Park Cache and my GPS took me all the way to the far corner of the park to look for it. I looked all around and couldn't see it. Then I went on my phone and grabbed the coordinates and tried to follow that, that took me to another location.

Meanwhile, the family that joined me to find the first one today showed up and went straight to Geocache and found it with little issue. I was standing about 30-50 feet away (which is how much the *tad* was) watching all of this.

I used the link that Quasi gave me to update the software in my unit and went to the first one I found today and used that as a measuring tool. It's more accurate now and puts me alot closer to where it was at compared to the first six times I tried to find it. :P
Rickhrrunka on November 28th, 2009 11:17 pm (UTC)
Hmmm. 30-50 feet sounds like WAAS wasn't doing its thing. Could be it just hadn't settled properly, I guess. I've seen a unit take an hour or more to get stable with WAAS. Might also be an incorrect datum setting (something other than WGS84) perhaps? Here in the UK the common mistake is to use the Ordnance Survey datum rather than WGS84.

Wildfox: surprise!wildfox34 on November 28th, 2009 11:40 pm (UTC)
It was set to WGS84 the entire time... maybe it was WAAS goofing up. Although, not sure why... I wasn't in a deep forest and it was a clear and sunny day today.
Rickhrrunka on November 29th, 2009 12:49 pm (UTC)
Could be the cache was hidden a while back when fewer folks could use WAAS, so the listed co-ords are a tad off? The other folks could just have had good cacher's eye; you walk into the area, think "Now where would I hide a cache?", go there, and find it.
Wildfox: amusedwildfox34 on November 29th, 2009 03:28 pm (UTC)
It was hidden back in April and the other Geocacher that was in the park with me found it with no issue. The person that hid it is pretty good at hiding these, I mean... they REALLY blend in well with the enviorment.

I did the software update that Quasi suggested and checked it with one that I found earlier and it's putting me a little more on target now, so hopefully it's fixed. :)