Brand Precision

[K618]

I know GeoCache coordinates are only as accurate as that recorded by the creator of the cache.

 

I'm beginning to wonder whether Garmins are more precise to Garmins, and Magellans to Magellans.

 

Of caches I've visited, I've found that the coordinates are either spot-on or 8-10 yards off.

 

Any research or experience on this?

[+EraSeek]

I doubt if that is true, but an interesting thought that I've never heard or considered before!

 

I've stood on top of horizontal markers before and had the reading dead on with my Garmin, so if this is true then you'll have to blame those darn Megellans.

 

[3fros]

To find out you need to be able to collect data. Good luck getting people to cooperate.

 

I posted This poll, because I wonder what others are using. For example, on this cache the original coordinates were off by 64 feet if I remember right from the location I came up with using my Platinum. Evergreenhiker had the original coordinates at 14' away, what was he using? What did Granny1918 use to come up with the original coordinates? Moun10bike's coordinates were around 50' from the original coordinates and he is using a Garmin V I believe. Was the owner using a V or a Platinum, or something completely different? Was VPlaMar, who had the same problems I originally had, using the same GPSr as me or something different? Was my Platinum consistently wrong at this cache location or was Granny1918's wrong.

 

My point is that without the data no one knows.

[+GOT GPS?]

I have alot of data gathered on this cache:

http://www.geocaching.com/seek/cache_details.aspx?ID=10951

 

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My home page about GPS units and information

[+Renegade Knight]

Two of us have Garmins and Two more of us have Magellans. They are pretty close to the same when it comes to where a cache is at. We are talking no more than 6' difference most of the time.

 

Wherever you go there you are.

[+SteveL]

If a cache is placed with a GPS with an error (A), and it is then hunted with a GPS with an error (, the two errors will create a new error, which is the sum of the two errors ©. The two errors will never cancel each other, but will always guide the cacher into the least desirable terrain.

 

SteveL

 

These are my opinions and only my opinions, unless you share them as well, which would make them our opinions, but I am not of the opinion that I can express your opinion as my opinion without your prior expression of said opinion, and then my re-utterance of that opinion would, in my opinion, be foolish unless I were expressing agreement to your opinion, and then it wouldn't be my opinion but your opinion to which I only agree.

[+Confucius' Cat]

I am new to the sport and am ussing a Garmin street pilot.

 

I have used it for several years for road navigation, but find some akwardness in geocaching.

 

I often find coords 50' or more off when using it in the woods, but have had occasions where (using with active roof mount antenna) I have driven to zero point and found cache within just a few feet.

 

I am wondering if it would be worthwhile to get a handheld unit- for reasons of accuracy and resolution- Read on for other drawbacks of street pilot:

 

* The maximum zoom screen is 200'.

* the direction arrow turns to a checkered flag and is useless at about 400' or so

* in max zoom, with track up, (see checkered flag comment- track up is only way to get even minimal directional arrow at close range), the resolution is little more than 1/4" on the screen.

* I am lazy and unmounting it from the dash and installing the supplied antenna slows me down when I want to jump out and catch a cache (OK, so I would still have to wait for the handheld to get a signal- what can I say)

 

I have used a Lowrance handheld in the past and seem to recall more accuracy (or at least more resolution) at maximum zoom. I am going to try to get ahold of it again and see if I like it better.

 

Anyone know of a handheld that would work better than the street pilot? I am especially interested in more resolution at close range.

 

Dave,GDAE

[+Cachetrotters]

quote:

---

Originally posted by SteveL:

If a cache is placed with a GPS with an error (A), and it is then hunted with a GPS with an error (, the two errors will create a new error, which is the sum of the two errors ©. The two errors will never cancel each other, but will always guide the cacher into the least desirable terrain.

 

SteveL

 

---

 

Since errors A and B are probability errors, they will combine as the root sum square[RSS]: Sqrt [(A^2)+(B^2)]. Two 30ft errors would more likely yield a 42.4ft error, which is still significant, but better than 60ft.

[+phantom4099]

There may be some diffrences since each uses diffrent formulas for measureing data (like the shape of the earth, and diffrent agolrithoms(?) for basic ionosphere corrections) and this may cause certain diffrences between recievers, but I doubt that it would cause the readings to vary much (may not even be noticable).

 

Wyatt W.

 

The probability of someone watching you is directly proportional to the stupidity of your actions.