Unreliable Coordinates

[PamD]

I recently placed a cache in a wooded area. Two very experienced GPSrs could not find the cache so I went back and refigured the coordinates. The first lat/longs were 53 feet away from the second set. A couple of days later, after having a chance to check out my GPS, I went back and verified that the second set of coordinates were unchanged with 6 satellites in 'view'. My FTF posted that the coordinates were off 11.5 feet. So...is there a general rule on what constitutes accurate enough? I know there is some inherent variation but at what point do I say I either don't know how to use my GPS correctly or I need a better model? Thanks for any thoughts on this......

Edited July 24, 2007 by PamD

[+Bill & Tammy]

I recently placed a cache in a wooded area. Two very experienced GPSrs could not find the cache so I went back and refigured the coordinates. The first lat/longs were 53 feet away from the second set. A couple of days later, after having a chance to check out my GPS, I went back and verified that the second set of coordinates were unchanged with 6 satellites in 'view'. My FTF posted that the coordinates were off 11.5 feet. So...is there a general rule on what constitutes accurate enough? I know there is some inherent variation but at what point do I say I either don't know how to use my GPS correctly or I need a better model? Thanks for any thoughts on this......

 

If you can get me within 20-25 feet of an ammo can hide I am happy.

[+Miragee]

Having coordinates off by 11.5 feet is no problem, especially in a wooded area, so I sure wouldn't worry about that. If I thought my coordinates would be less than accurate, I would mention that in the cache description and then would have a detailed/specific hint, so anyone making the trek to the location would still be able to find the cache.

 

Just curious . . . what kind of GPSr do you use?

[+TrailGators]

Having coordinates off by 11.5 feet is no problem, especially in a wooded area, so I sure wouldn't worry about that. If I thought my coordinates would be less than accurate, I would mention that in the cache description and then would have a detailed/specific hint, so anyone making the trek to the location would still be able to find the cache.

 

Just curious . . . what kind of GPSr do you use?

11.5 feet is very good in woods. You should let your GPS settle for a few minutes and then take an average of several readings. Many GPSs have a built in averaging function.

[+the hermit crabs]

I recently placed a cache in a wooded area. Two very experienced GPSrs could not find the cache so I went back and refigured the coordinates. The first lat/longs were 53 feet away from the second set. A couple of days later, after having a chance to check out my GPS, I went back and verified that the second set of coordinates were unchanged with 6 satellites in 'view'. My FTF posted that the coordinates were off 11.5 feet. So...is there a general rule on what constitutes accurate enough? I know there is some inherent variation but at what point do I say I either don't know how to use my GPS correctly or I need a better model? Thanks for any thoughts on this......

I just looked at the FTF's log. He didn't say that the coords were off by 11.5 feet -- he posted alternate coords, and indicated that his GPS was showing 11.5 ft accuracy when he obtained them. The actual difference between his coords and the posted coords on the cache page is 50 feet.

[+the hermit crabs]

(deleted duplicate post)

Edited July 24, 2007 by the hermit crabs

[+StarBrand]

50 feet is getting close to too much. I generally figure coords will get me within 25 - 30 feet or so. That is the average accuracy of our handheld units. But 50 feet off is not terrible. If you have better, use them. Easy enough to do a change log for that.

[+briansnat]

Under 30 feet is ideal, but 40-50 ft off is common and I wouldn't even mention it in the log.

 

Once you start getting over 50 feet it becomes an issue. If the coords are 70+ feet off I will probably note that fact in the log.

[+JohnnyVegas]

If you are really concerned about geocachers finding the cache due to tree cover you can add a hint that would narrow down the places to search

[+briansnat]

If you are really concerned about geocachers finding the cache due to tree cover you can add a hint that would narrow down the places to search

 

That is what I do in areas where reception is problematic. I make the hint as specific as possible.

[+Thrak]

Don't feel too badly about the coordinates being a bit off. I recently missed a FTF attempt because the coordinates were 3.5 MILES off. I missed another FTF attempt (from the same cache hider) because those coordinates were over 10 MILES off - on the other side of the mountain. She sometimes simply gets the coordinates messed up when entering the cache listing.

 

I've found caches where the coordinates were 110 feet off - another FTF but this time I found it. I posted corrected coordinates to help others with the find. When I hide a cache I try to make sure the coordinates are as accurate as possible. I let the unit "settle" and then I have it average the coordinates for around 100 iterations. Then I walk away from the cache and approach from various directions to see if the unit actually gets me to the cache using my selected coordinates.

 

I've had a couple of folks tell me one of my caches had the coordinates off by over 25 feet. Others have said the coordinates were spot on for the same cache. It may be annecdotal evidence but, it seems to me that the Magellan users are always the ones who tell me my coordinates are funky and the Garmin users are always the ones who tell me the coordinates are right on the money. It makes me wonder if the two figure coordinates in a slightly different manner.

 

We have a local cache hider who sometimes has excellent coordinates and sometimes has funky coordinates. He uses both a Magellan and a Garmin. I've often wondered if the ones I have trouble with were listed using the Magellan and the ones I find very close to the listed spot were placed using the Garmin.

[+Miragee]

I recently placed a cache in a wooded area. Two very experienced GPSrs could not find the cache so I went back and refigured the coordinates. The first lat/longs were 53 feet away from the second set. A couple of days later, after having a chance to check out my GPS, I went back and verified that the second set of coordinates were unchanged with 6 satellites in 'view'. My FTF posted that the coordinates were off 11.5 feet. So...is there a general rule on what constitutes accurate enough? I know there is some inherent variation but at what point do I say I either don't know how to use my GPS correctly or I need a better model? Thanks for any thoughts on this......

I just looked at the FTF's log. He didn't say that the coords were off by 11.5 feet -- he posted alternate coords, and indicated that his GPS was showing 11.5 ft accuracy when he obtained them. The actual difference between his coords and the posted coords on the cache page is 50 feet.

Oh . . . that makes all the difference. It would be interesting to know what kind of GPSr the FTF has. If it is one with the high-sensitivity chip, like a Garmin Map60Cx/CSx or 76Cx/CSx, that explains the good accuracy. If it isn't a GPSr with the new chip, and they could get accuracy like that, maybe the OP does need a newer GPSr.

 

Fifty feet is a bit too far off, even under trees, although a specific hint can compensate for "unreliable coordinates."

[+CurmudgeonlyGal]

I've found that different areas expect different things from their cache placers and the cache coordinates.

 

I was caching in one area over a period of some time and was realizing that while the coordinates were sometimes off in an appreciable manner, NO ONE mentioned this in their logs. I was amazed at the lack of note, and also amazed at the poor coordination as it was VERY easy to get enough satellites that have single digit accuracy readings on the GPSr (please, no discussion over how accurate the accuracy is... been there, done that).

 

Eh. It was just expected and everyone rolled with it. I did ask one of the more prolific people in the area what was up with that and he said that unless it was 60 to 80' off, nobody said anything.

 

I managed. It was tough. However, I've noticed that my time there has carried over. I'm MUCH less inclined to take the time to whine about coordinates, and/or to post new ones after being in with the other crowd for a time. (This doesn't, of course, mean I don't whine about OTHER things, though.)

 

Around here people complain loudly and clearly. I'd venture to guess that 40' off would get a mention, new coords posted and make people less than happy. Of course, everyone could still find it, but that's not the point.

 

One of my more enjoyable logs to write started off like this:

 

N 47° 20.302 W 122° 01.259

Hey, only 300 feet off on your first cache. That's not too bad!

 

New coords at cache location: n47 20.302 w122 01.259

 

The difficulty and terrain ratings (now that this has been located - Wahoo!) are probably more like the original set - Difficulty is clearly a 1 and terrain is a 1.5 or a 2... if you find the little spur trail there's no bushwhacking at all and the trail goes right by the cache. Couldn't be much easier, right?

 

There were a few DNF's on that one.

 

 

michelle

Edited July 24, 2007 by CurmudgeonlyGal

[+Renegade Knight]

Less than 50' I'm not going to say anything. It's normal. More than 50' and I'll think about it. If it's still easy...it doesn't matter.

 

One cache at about 250' off got my butt chewed by the owner (An Engineer) because obviously they knew all about coodinates and would never make such a mistake.

[+Miragee]

Recently I was revisiting a location where a friend hid a Micro in a rockpile. There was a recent DNF, and if I had not been with someone else the day we were FTF, I probably would have called it a DNF.

 

So, my friend started his search a good 15-20' south of where the cache was hidden. Since we had other caches to hike to that evening, I gave him a few Hot/Cold hints until he found the hiding place. While he signed the log, we took new coordinates.

 

I didn't pay any attention to the numbers; I just emailed them to the cache owner the next morning . . . they were 5.8 feet off from the original coords . . .

[+Mr_Mikey]

I have been pretty lucky on most of the cashes I have found, they have gotten me within 15 feet of the cache. When I cannot find one I will find the spot the posted coordinates say where the cache is, and come at it from different directions trying to find a center point and then work my way out from there. This has saved me in heavily wooded areas.

There may be a better way and someone with more experience might post it, but on the average I would say I am within 25 feet by using the posted coordinates which after reading these posts is very good marking.

I have used WAAS on some difficult caches and gotten within 5 feet of the cache.

I use a garming legend.

[+Harry Dolphin]

Less than 50' I'm not going to say anything. It's normal. More than 50' and I'll think about it. If it's still easy...it doesn't matter.

 

One cache at about 250' off got my butt chewed by the owner (An Engineer) because obviously they knew all about coodinates and would never make such a mistake.

 

Yeah. Got a log deleted for mentioning that the final cache location was 170' off. I did not post the coords of the find, just that it was 170' off. Relogged with SLTNLN. Ain't looking for any more of his caches...

[+HaLiJuSaPa]

There's a new hide here in which the coords were about 300 FEET off! But once a couple of people noted it in the logs she was very good natured about it (it was her first hide) and she corrected accordingly. Happens to the best of us, don't worry, be happy!

[+briansnat]

Yeah. Got a log deleted for mentioning that the final cache location was 170' off. I did not post the coords of the find, just that it was 170' off. Relogged with SLTNLN. Ain't looking for any more of his caches...

 

Who ARE these cache owners you keep running into?

[+Harry Dolphin]

Yeah. Got a log deleted for mentioning that the final cache location was 170' off. I did not post the coords of the find, just that it was 170' off. Relogged with SLTNLN. Ain't looking for any more of his caches...

 

Who ARE these cache owners you keep running into?

 

Ah, Brian. I have been known to cache in all sorts of strange places. That one would have been in Saddle River. On any given weekend, you might find us anywhere from Pike County PA/Orange County NY across north or central Jersey, into The City. We were in Prospect Park, Brooklyn a few weeks ago, and met a couple from The Bronx who exclaimed: It's Harry Dolphin and Andy Bear! Had the same greeting a month ago in Watchung Reservation from a couple from Yonkers. And early this year in Westfall, PA. It's a strange hobby.

[PamD]

I want to thank everybody for taking the time to respond to my question. All the info was helpful. As a matter of fact, the forum and all the people who went looking for the cache were very helpful and gracious with their time. I've learned a lot. This cache...naturally!...is in a park with an entrance fee. The woods are hot, humid, buggy and sticky...of course. That doesn't sound to me like a recipe for fun (though I was assured the hunters knew what they were getting in for) and I want this to be fun. And interesting. I think the cache is going to meet my goals now and my problems should be solved. Plus, I now know a couple different ways to double check my coordinates that I didn't know before so that bodes well for the future.

 

Again, many thanks to all of you......PamD

Edited July 25, 2007 by PamD

[+CurmudgeonlyGal]

Yeah. Got a log deleted for mentioning that the final cache location was 170' off. I did not post the coords of the find, just that it was 170' off. Relogged with SLTNLN. Ain't looking for any more of his caches...

 

I love it when my logs get deleted... Gosh, I can't imagine why you wouldn't want someone to know this is a DUMPING area... or ???

 

I haven't had one deleted for mentioning that a particular cache was x' off... but I have had them encrypted for the same reason.

 

WHY would a cache owner delete OR encrypt them b/c you mentioned the coordinates were THAT far off? In my case people were DNF'ing this particular cache right and left... I came, I saw, I conquered... I posted new coords and mentioned how far off it was.

 

So mine gets encrypted?

 

No worries. I know how to 'fix' permanently encrypted logs. Sheesh.

 

 

michelle

[+briansnat]

Yeah. Got a log deleted for mentioning that the final cache location was 170' off. I did not post the coords of the find, just that it was 170' off. Relogged with SLTNLN. Ain't looking for any more of his caches...

 

I love it when my logs get deleted... Gosh, I can't imagine why you wouldn't want someone to know this is a DUMPING area... or ???

 

I haven't had one deleted for mentioning that a particular cache was x' off... but I have had them encrypted for the same reason.

 

WHY would a cache owner delete OR encrypt them b/c you mentioned the coordinates were THAT far off? In my case people were DNF'ing this particular cache right and left... I came, I saw, I conquered... I posted new coords and mentioned how far off it was.

 

So mine gets encrypted?

 

No worries. I know how to 'fix' permanently encrypted logs. Sheesh.

 

 

michelle

 

Some nitwits purposefully post bad coords to add to the "challenge". You might have run into one of those bozos.

[+hukilaulau]

It may be annecdotal evidence but, it seems to me that the Magellan users are always the ones who tell me my coordinates are funky and the Garmin users are always the ones who tell me the coordinates are right on the money. It makes me wonder if the two figure coordinates in a slightly different manner.

 

We have a local cache hider who sometimes has excellent coordinates and sometimes has funky coordinates. He uses both a Magellan and a Garmin. I've often wondered if the ones I have trouble with were listed using the Magellan and the ones I find very close to the listed spot were placed using the Garmin.

My guess is you're right, it is anecdotal. Kind of like, "An ace always hits the board when I have pocket kings"

I've used both a varmint, oops, sorry... garmin and a magellan at the same time on the same cache, and it's nearly always the magellan that puts me right on top of the cache no matter what it was hidden with...

Edited July 25, 2007 by hukilaulau

[+jwe4i]

there are things that seem to mess with the gpsr sometimes, cloud cover, trees, and powerlines are a few. i usually take to readings before posting the coords.

[+Thrak]

there are things that seem to mess with the gpsr sometimes, cloud cover, trees, and powerlines are a few. i usually take to readings before posting the coords.

 

Cloud cover shouldn't have any effect...

[+HaLiJuSaPa]

I want to thank everybody for taking the time to respond to my question. All the info was helpful. As a matter of fact, the forum and all the people who went looking for the cache were very helpful and gracious with their time. I've learned a lot. This cache...naturally!...is in a park with an entrance fee. The woods are hot, humid, buggy and sticky...of course. That doesn't sound to me like a recipe for fun (though I was assured the hunters knew what they were getting in for) and I want this to be fun. And interesting. I think the cache is going to meet my goals now and my problems should be solved. Plus, I now know a couple different ways to double check my coordinates that I didn't know before so that bodes well for the future.

 

Again, many thanks to all of you......PamD

 

Many cachers have done quite a bit of hiking/nature walking in their pre-caching life and expect the places they go to to be hot, humid, buggy and sticky and just accept it and come prepared with bug spray, etc. It's often worth it to see the natural world, a great view, just get out and about, etc. Also, most people here are going to be helpful, we don't want to turn people off to the activity.

 

And believe me, a cache with problem coords can easily turn around once it's fixed. The "300 ft. off" cache I mentioned earlier just got a find from a person who was visiting the area on a business trip and chose the cache because he/she thought it would be a great cache and now easily found with the new coords sees that they were right. Good luck and cache on!

[+Team Cotati]

I find a cache that is 50' from the posted coords........I log that fact. Never once been challenged.

 

As to the original point of the OP. I don't know what specific GPSr that she carries. I do know that, barring some defect or other, if it was manufactured in the past 4-5 years, that in all likelyhood it is plenty accurate enough for this game. But hey, if you have the coin enough to go out and purchase a new gpsr everytime that a new generation comes on the market, regardless if it provides any important functionality......go for it. If hunters consistiently complain about the accuracy of your posted coords you might take a pal along to double check or just borrow his gizmo. If you are continually finding caches at coords that are significantly different from those posed........do the same check. As near as I can tell, this scenario is very rare indeed but no electronics are 'perfect'.....some however are close. I for example have an 'older' unit and I can tell you that it is as 'accurate' as most anything out there. I have an older car and TV too, they work equally well. But like I said, if I had the coin and couldn't think of anything better to do with it, I'd go out and get me one of them $5,000.00 TV's and a brand new shiny Bentley.

 

You don't need a 'better' model. You need a model that gets the job done and fits within your needs and budget. Not really THAT different than most other purchase decisions in life....is it?

Edited July 28, 2007 by Team Cotati