Yellow Etrex Seems To Drift

[+LeslieRN72]

During my last two caches, I've noticed my yellow Etrex really seems to drift. I'll be right on the spot, then it will say I'm 30 or more feet away. It seems like I'm running back and forth trying to get the Etrex to read right on. Is this normal or is something wrong with my Etrex?

[+Lockjaw]

I get the same thing. I'm assuming you're using the eTrex, right? It's frustrating when you think you're right on top of a cache, then you look again and you're 30 ft away. I've had it less than a week (got it on eBay VERY cheap) and started looking for a better unit today.

 

LJ

[+Bob Blaylock]

  What you are experiencing is perfectly normal.  That's just the limitations of the basic GPS protocol.

 

  GPS is nominally specified to be accurate to 15 meters.  That's roughly 45 feet.  Often, you'll get better accuracy than that; sometimes, you'll get worse.  As satellite positions change, and as you get different signals from different sattelites, the calculated position will often shift, as has been described.

 

  Many of the newer GPS units support WAAS, which enables greater accuracy.  I don't have a WAAS-enabled GPS, so I don't have any firsthand experience to report, but I am given to understand that WAAS can sometimes be rather iffy in some places, but when it does work, your accuracy is nominally around 3 meters instead of 15.

 

  I'm also aware of a feature called Differential GPS (or DGPS), which a yellow eTrex can apparently be equipped to support (at what cost, I do not know, nor do I know how widely available the DGPS sigansl are (I believe DGPS signals come from ground-based stations)) that, when available and used, also greatly improved GPS accuracy.

 

  Other than using WAAS or DGPS or perhaps some other GPS-enhancing system that works on similar principles, no GPS is going to give very much better accuracy than any other.  Among all GPS receivers that do not use any such technology, your basic yellow eTrex can be expected to be as accurate as any other.

[+briansnat]

I get the same thing. I'm assuming you're using the eTrex, right? It's frustrating when you think you're right on top of a cache, then you look again and you're 30 ft away. I've had it less than a week (got it on eBay VERY cheap) and started looking for a better unit today.

 

LJ

You can buy a better unit, but you will have the same results.