Which direction?

[+azhiker2000]

Love this site! I found my first cache over the weekend and am totally hooked on geocaching! I thought it would be easy to start with the caches that were closest to me, the micro caches. On two searches yesterday, I had the same problem, however, and hoped someone here could help.

I have an eTrex Legend. As I approached the cache, my eTrex said I was heading in the correct direction, and was within 20 feet. However, as I slowly got closer, the eTrex suddenly pointed in the opposite direction and read that I was around 80 feet from the cache. It did this on two different caches.

The first cache had some trees around, so I wandered in different directions, trying to get a better fix. The second cache had a building nearby, but wandering around still gave me the same result.

Is there something wrong with my eTrex? Me?

[darkfrog]

The problem is probably that you are expecting too much accuracy from a consumer grade GPSr. On a good day you can only expect the unit to get you within 30-40 ft of the cache, then you're on your own... Such is the thrill of the hunt.

 

IT Ninja for Hire|High-Tech Adventures

[+azhiker2000]

Oh, my! I thought I should get within 10 feet of the cache, then I was on my own. 30-40 feet sounds like a real challenge!

Thanks for the insight.

[give-n-takes]

Have no fear,I had the same problem. I found that if I was really close and was going really slow and turning different directions, I "confused" my GPS. Once I know my general area say within 30 feet, I try to make sure I look around for physical hints or look ahead to determine which path I'll take if it's brushy or lots of fallen trees are around. This way my GPS has an easy time of it and now I get in closer than twenty feet and start using my eyeballs. The one time I had a real problem after making my GPS discovery, the cache was on a rock formation above my peabrained head-duh-no wonder my poor little GPS "inaccurate". It was error of the user!By the way my gps is a yellow so it's not pricey, but amazingly accurate, trust your GPS, it will tell you things! Hope this helps! Happy Hunting!

[+Houston Muggles]

I have the basic eTrex, I think the most inexpensive one there is. Sometimes you will find the accuracy to be withen 15 feet. When my husband and I were out yesterday it took us straight to one at 0 feet. Sometimes you'll feel like its pointing you in circles but if you just keep walking towards the direction its pointing you it will point you back so you'll get the jest of where it is. You will find that the accuracy can pinpoint it very close sometimes. The legend is more expensive than mine, so Im sure the more you do, you'll notice the difference.

[+briansnat]

You have to be moving for the directional arrow to work. As you get closer to the cache, people tend to slow down, which causes the needle to point all over the place.

 

You also have to factor in that the cache placer had a margin of error when the cache was placed. So add his margin of error to yours and you could be off 50 or more feet.

 

One way to narrow down the location is to start circling the area when you get to within 60 feet or so. Watch the needle and if it stays pointed at the same spot in the middle of your circle, you have a pretty good idea where the cache is.

 

"Give a man a fish, he'll eat for a day. Teach a man to fish, he'll sit in a boat and drink beer all day" - Dave Barry

[fab44]

FYI the compass on the eTrex Legend works off the satellite GPS signal - it's NOT an electronic compass (which reads magnetic north). What this means is the Legend (and most of the other eTrex models) needs a clear view of the sky AND you need to be walking for the compass to work. Once you stop walking, the Legend will get get confused and the pointer may do a 180. This is normal.

 

The best way to find a geocache is to watch your GPS until you get within 25 feet of the cache. Then put the GPS in your pocket and start looking around for the geocache.

[+azhiker2000]

Thanks, everyone! I did slow down to almost a standstill when I approached "the site", and when I began to walk again, that's when I got the 180° change. I did have an idea of where the caches were, and it sounds like I should have just put the GPS away and headed in that direction. I love this sport!

[+Mark 42]

This site (URL Below) doesn't speak highly of the Etrex, but I think maybe it's an old site, and judging by how many people here seem to like the Etrex, it may be inaccurate.

 

http://gpsinformation.net/main/gpshiking.htm

 

I would like to know which ones work best in the trees.

 

Hukt un fonix werkt fur mee

[yeahright]

(from a previous post)

 

No matter how precise you think you are, you still have to deal with accuracy. Most units give an estimate of “gps accuracy” or EPE “estimated position error”. These are evidently numbers the unit has calculated from the variation of the received position information. This is an estimate – it has it’s own lack of accuracy.

 

We’ve all observed that when you get to “ground zero” , it keeps moving around. The bearing and distance fluctuate wildly. While standing still you can observe with great precision that the cache is 8 feet away, no, it’s 27 feet, no wait a minute, now it’s 53 feet away, hey now it’s 17 feet away.

 

To be practical, when cache hunting, it has become my habit to stand off about 100 feet while my son starts searching under rocks, bark, limbs or whatever. Over several minutes I watch the distance and bearing display and observe the minimum/maximum distance to the target as well as the minimum/maximum bearing changes. Using a real compass, I then can determine the target area. The cache is usually, sort of, in the middle region of the target area. You have to keep in mind that when the cache was placed, the cache owner’s GPS gave them a position with some inaccuracy also.

 

This approach works well when the target area is in a position of poor GPS reception. Step back to an area with a better skyview and then determine the target area.

 

Keep working with it and you’ll get the hang of it. Then you’ll buy another unit with better features thinking this is the Holy Grail and that you’ll not have any more uncertainties. But even with better precision, the new one will still have to deal with lack of accuracy.

 

Faster, Better, Cheaper

Pick any two.

[+azhiker2000]

Thanks, YEAHRIGHT. I hope that getting a few more finds logged will help me to understand my GPS better, and the two of us will learn to work together. Kinda hard at first, though.

[+mrmnjewel]

Hey Hiker,

I understand where you're coming from...We were having (and still am) similar issues...It's part of the game...Part of the fun...

 

The kingdom of heaven is like treasure hidden in a field. When a man found it, he hid it again, and then in his joy went and sold all he had and bought that field.---Matthew 13:44

 

Matt & Julia

 

To view our online geocaching diary/blog, click here

I wish outer space guys would conquer the Earth and make people their pets, because I'd like to have one of those little beds with my name on it.

- Jack Handey (aka Jack Handy)

[+Alan2]

All the etrexes have the same accuracy. The difference among them are the features. Some have electronic compasses and altimeters others don't. SOme have mapping features others don't. Some have bigger memrories, etc.

 

But the basic function ofm indicating to the waypoint are the same given the same set of circumstances. (tree cover, the way you're holding it, etc.)

 

Alan

[+Cat'N'Geo]

That way!-------->

<------um no.

 

They say this universe is bound to blow,

I say we crank up the Calypso Control!

~Jimmy Buffett

 

~Someday I Will~

[2oldfarts (the rockhounders)]

quote:

---

Originally posted by darkfrog:

The problem is probably that you are expecting too much accuracy from a consumer grade GPSr. On a good day you can only expect the unit to get you within 30-40 ft of the cache, then you're on your own... Such is the thrill of the hunt.

 

http://www.callblog.net|http://geo.callblog.net

 

Our unit consistently puts us with-in 25 feet of a waypoint and frequently 10 feet and less.

I would suggest you place an object close to where you live and set about 5 waypoints for it. After each waypoint move away in a different direction and come back to take the next reading. Then take an average of the five waypoints and use this as the only waypoint for the object. Now leave the area entirely and do a goto for the object. This will let you learn how to read what your unit is telling you since you already know where the object is located. Try coming at it from different directions and different conditions (open spaces, heavy trees, overcast skies, etc.). Also use a compass with your GPSr for headings and bearings. This helped us to learn our unit quick and easily and it was fun too boot. In just a couple of days you'll be amazed at how well you will be doing.

Have fun.

 

John of 2oldfarts

 

There's only two rules to life.

1st - don't sweat the small stuff.

2nd - It's all small stuff...

[DanIAm]

quote:

---

Originally posted by 2oldfarts (the rockhounders):Our unit consistently puts us with-in 25 feet of a waypoint and frequently 10 feet and less.

I would suggest you place an object close to where you live and set about 5 waypoints for it. After each waypoint move away in a different direction and come back to take the next reading. Then take an average of the five waypoints and use this as the only waypoint for the object. Now leave the area entirely and do a goto for the object. This will let you learn how to read what your unit is telling you since you already know where the object is located. Try coming at it from different directions and different conditions (open spaces, heavy trees, overcast skies, etc.). Also use a compass with your GPSr for headings and bearings. This helped us to learn our unit quick and easily and it was fun too boot. In just a couple of days you'll be amazed at how well you will be doing.

Have fun.

 

John of 2oldfarts

---

 

How do I go about figuring out the average of mutiple readings?

 

Thanks,

GeocachingGuy

[+beejay&esskay]

quote:

---

Originally posted by GeocachingGuy:

How do I go about figuring out the average of mutiple readings?

 

Thanks,

GeocachingGuy

---

 

Add up the latitude numbers and divide by how many you added.

 

Degrees are most likely the same, so you can ignore that. Just add up the minutes (in decimal) and divide.

 

(Then repeat for longitude.)

 

If that's not clear, post and example and what my calculation gave you and I'll correct it, if needed.

[+quills]

all the replies here are accurate. i have a legend and have found that in heavy cover it's best to get close about 20-30 ft and when it starts going crazy i come in from a different direction until it says 20-30 ft. this actually helped me find one last night that was in some tree cover. i hope this helps.

 

"If you mess with a Porcupine you might just get the quills. LOL I just had to say that"

[+Mark 42]

Remember, your own head can block out one or more sattelites from reaching the antenna.

 

Sometimes I will hold my GPS unit up high for a couple of minutes, or set it on something like the top of a tall tree stump, and walk away for a few minutes (search the immediate area).

 

This was particularly useful on my older unit. My new SporTrak Pro amazes me at how well it works in the forest.

 

But even with my new unit, I sometimes catch myself holding it too low.

 

Also, I like to place it near the left side of my dashboard when driving in tree lined roads... that puts it nearer the centerline of the road, and farthest from the greatest number of trees.

 

BTW, do those Rebroadcast Antennas work well?

 

[This message was edited by Mark 42 on August 09, 2003 at 05:03 PM.]

[+azhiker2000]

Thanks for the great ideas! I'm going to try what 2OldFarts suggested, and set an object in my backyard and approach it from different directions. I'll see if I can avoide the 180° change of direction by continuously walking, instead of stops and starts.

[+TheCacheCows]

Go buy yourself a $10 compass. The GPSr has the correct bearing to the location it just doesn't know what direction you are traveling.