Accuracy of 60Cx

[GastonFam]

Just got my first GPS, a Garmin GPSmap 60 Cx. I understood that the accuracy was supposed to be down in the +/- 3ft range. Mine never gets better than about +/- 14ft (according to the satelite screen), even with WAAS enabled. The satelite screen even shows that it's locked on to 8 or 10 satelites prett good. Is there another setting somewhere I should be looking for somewhere?

 

Thanks

[+StarBrand]

Your not missing anything. Re-read the the fine print. The absolute best accuracy you will see is about 3 meters or about 9 feet. On average it will be between 15 and 20 feet. On rare occasions you will see about 6 feet.

 

What you are actually seeing is a best guess of something called EPE. Estimated Position Error. It is only an estimate. Even if it said zero - it is only an estimate based on the current sat geometry and other conditions. It means that something like 85% of the time under the current conditions, the reading is estimated to be within xx feet of the actual position.

 

When you go Geocaching, remember the hider may have been up to 30 foot off due to EPE and you may be 30 foot off due to EPE - so it is not unreasonable to have to look in a 60 foot radius to find the cache. Usually, on average it will be much closer but could be that far away and still be normal.

[+Prime Suspect]

Just got my first GPS, a Garmin GPSmap 60 Cx. I understood that the accuracy was supposed to be down in the +/- 3ft range. Mine never gets better than about +/- 14ft (according to the satelite screen), even with WAAS enabled. The satelite screen even shows that it's locked on to 8 or 10 satelites prett good. Is there another setting somewhere I should be looking for somewhere?

 

Thanks

Don't know where you got that 3 foot number, but it's wrong. Garmin specs list it as 3 to 5 meters, with WAAS enabled.

[+Kabuthunk]

Yeah, I've only once seen mine hit 3 meter accuracy. Sometimes it's 4, most often it's 5.

[+Renegade Knight]

Once WAAS has had some time, you will start seeing accuracy below 10'. It won't be consistant but it will happen.

[+TrailGators]

Once WAAS has had some time, you will start seeing accuracy below 10'. It won't be consistant but it will happen.

Now if we only knew which direction to go the last 10 feet....

[+dkwolf]

My legend would routinely display EPE of 7 ft, while my 60CSx the best I've seen is 9. No matter. If I'm that close, I'm happy.

[+TheRoadKing]

Just located my first cache this morning, using new GPSMAP 60CSx. The compass page initially got me withing 3 feet of the cache with the compass arrow pointing right at it but I had some trouble because when I moved closer the arrow would rotate off to a new direction and distance. I eventually found the cache by backing off about 10' and starting over several times and then crawling around on the grass looking under the most likely boulder.

 

My GPS's position format is set to the default hddd mm.mmm'...map datum WGS84. Are these the correct units used by everyone in hiding and finding the caches?

[+trooperdjb]

Just located my first cache this morning, using new GPSMAP 60CSx. The compass page initially got me withing 3 feet of the cache with the compass arrow pointing right at it but I had some trouble because when I moved closer the arrow would rotate off to a new direction and distance. I eventually found the cache by backing off about 10' and starting over several times and then crawling around on the grass looking under the most likely boulder.

 

My GPS's position format is set to the default hddd mm.mmm'...map datum WGS84. Are these the correct units used by everyone in hiding and finding the caches?

 

If you got within 3' you did great, considering your accuracy was probably in the 10' to 15' range and the hider's was also at best that good. When you get that close to GZ the small changes in the position readout accuracy will flip you around in any different direction, as you back off those changes aren't as big on a percent basis so it holds steadier even if it's no more accurate.

 

Yes your position format and datum are correct.

[+trooperdjb]

My legend would routinely display EPE of 7 ft, while my 60CSx the best I've seen is 9. No matter. If I'm that close, I'm happy.

 

I've noticed the same thing between my 60CSx and ForeTrex with the Foretrex often reporting a smaller error then the 60 but then bouncing to a significantly greater (3 or 4 times) error while the 60 stays fairly constant. From some reading I've done Garmin may have made a change in how they calculate the EPE on the newer X series units leading to it displaying a larger EPE even though it has a better lock on more sat's.

[+StarBrand]

Just located my first cache this morning, using new GPSMAP 60CSx. The compass page initially got me withing 3 feet of the cache with the compass arrow pointing right at it but I had some trouble because when I moved closer the arrow would rotate off to a new direction and distance. I eventually found the cache by backing off about 10' and starting over several times and then crawling around on the grass looking under the most likely boulder.

 

My GPS's position format is set to the default hddd mm.mmm'...map datum WGS84. Are these the correct units used by everyone in hiding and finding the caches?

Best advice is to put the GPSr away when you get within 20 feet or less and start looking at likely hiding spots. It will rarely point right at the cache. (see above)

[+StarBrand]

.... a larger EPE even though it has a better lock on more sat's.

Its not so much the number of or "lock" on the sats - what really determines the EPE is the angle between the various sats and your receiver. In general a few sats spread way apart in the sky will give a lower EPE then 6 or 7 clustered together in one part of the sky.

[+dkwolf]

Just located my first cache this morning, using new GPSMAP 60CSx. The compass page initially got me withing 3 feet of the cache with the compass arrow pointing right at it but I had some trouble because when I moved closer the arrow would rotate off to a new direction and distance. I eventually found the cache by backing off about 10' and starting over several times and then crawling around on the grass looking under the most likely boulder.

 

My GPS's position format is set to the default hddd mm.mmm'...map datum WGS84. Are these the correct units used by everyone in hiding and finding the caches?

Every experienced cacher on here will tell you, once you get to within about 30-40' of the cache location, STOP looking at your gps and start looking and thinking about where YOU would hide something. Once you get to within 40' or so, the compounding errors between your gps and the hider's gps make it (usually) pointless to try and follow the arrow.

[+Renegade Knight]

Once WAAS has had some time, you will start seeing accuracy below 10'. It won't be consistant but it will happen.

Now if we only knew which direction to go the last 10 feet....

That's why they invented the Hula Dance and the Drunken Bee Walk. So you can find Ground Zero when your GPS can't point the way.

 

There are two kinds of cachers.

Those who find Ground Zero,

and

Those who find the Cache.

Edited April 19, 2007 by Renegade Knight

[GastonFam]

Thanks for all the responses, guys. Guess I just remembered the wrong units from what I'd read and had feet comfused for meters. I've had no problem finding caches (especially with my kids to check the low spots), I was just mistakenly looking for a smaller +/- value. The 60Cx has put me dead on a couple of times, but usually, like folks have said here, the compas goes wacko when you get within 10 feet or so.