Incorrect Coordinates?

[+leenah]

Can anyone explain why, after a year or so of geocachers successfully finding our cache with its posted coordinates, we suddenly start getting DNF logs and angry cachers insisting our coords are wrong? Of course we go to the GZ to check on it, and without exception, we find the cache exactly where its always been. Today we took new marks and by comparison, they ARE indeed 26 ft off from the posted coords. We updated them in hopes it will make a difference, but the question still remains: What could cause such an occurence? Satellite variation? Earth rotation variance? Polar Vortex? []

[Moun10Bike]

This forum is for reporting of bugs and feature requests related to Geocaching.com. I'm moving this thread to the general forum.

[+T.D.M.22]

The co-ords don't change. I don't think 26 feet is bad, but you may have had the co-ords off to begin with, and nobody complained.

[7rxc]

I would hope that you did more than take one sample before changing your coordinates. A case like this one would deserve a thorough re sampling over several occasions. Short term averaging can help with the individual samples, but it can take several samples at different times of day, over several days to get things averaged well.

 

My only cache took 4 days over a year, one to three or four samples and then it still wants to be snarky about taking you back to GZ. Mind you we're talking a typical GZ radius of up to 10 metres. My concern was that I didn't want people going down hill in nasty terrain.. Anyway I got decently repeatable coordinates and added some spoiler photos as well. Now I'm waiting for summer to do some more checks. It depends on many factors, GPS vs phone and versions, satellite alignment and functionality, user skills, etc. Using good coordinates that are repeatable by several means (gear types) is the key.

 

Who knows, maybe your island has decided to move and you are among the first to notice. At least it sounds like it is 'available in Winter'. Mine is possible but not so far this winter... we are having a heat wave of sorts and the high today was -15C.

 

Doug 7rxc

[+leenah]

I think 7RXC is right, our island moved...

[4wheelin_fool]

26 feet used to be average but now its the new bad due to increasingly accurate units. In your case, I suspect its mostly others reading the last few logs and expecting similar results and mimicking others logs. Some people are at a loss of things to write and often read past logs and just write something slightly different. A single DNF can often trigger a chain reaction for no good reason at all.

[+cwgrizz]

In regards to a number responding of coords being off, I think that is becoming more of a norm now with the trial phone apps and new cachers. Some have the idea that their GPSr/smartphone should "Pin Point" the exact location of the cache. Most times this is not possible because of the GPSr/smartphone allowed accuracy. I have seen logs about finding the cache, but the coords needed to be changed because they were off by 10'?? I know that conditions can create different readings and to me even +/- 25-30' in some cases are acceptable, however difficult to find. Ha! Like a previous poster stated, do a number of readings with different conditions, times, and maybe even if possible GPSr's...

[+-CJ-]

A single DNF can often trigger a chain reaction for no good reason at all.

 

I've seen situations like that. When someone reports inaccurate coordinates the next person (who read the previous log(s)) is "prepared" in his mind that he may fail to find the cache because of inaccurate coordinates.

[+leenah]

A single DNF can often trigger a chain reaction for no good reason at all.

 

I've seen situations like that. When someone reports inaccurate coordinates the next person (who read the previous log(s)) is "prepared" in his mind that he may fail to find the cache because of inaccurate coordinates.

[+leenah]

We are starting to believe this is the case. But when someone says "we searched for almost an hour", it is really hard to fathom how they did not stumble across it. It's under a clump of weeds under a tree, and the clue says so....Maybe because the view here is so spectacular it is downright distracting?...

[+MKFmly]

A single DNF can often trigger a chain reaction for no good reason at all.

 

I've seen situations like that. When someone reports inaccurate coordinates the next person (who read the previous log(s)) is "prepared" in his mind that he may fail to find the cache because of inaccurate coordinates.

 

That does happen.

 

As a cacher how would you determine the coordinates are off if you have not located the cache?

[+colleda]

A single DNF can often trigger a chain reaction for no good reason at all.

 

I've seen situations like that. When someone reports inaccurate coordinates the next person (who read the previous log(s)) is "prepared" in his mind that he may fail to find the cache because of inaccurate coordinates.

 

That does happen.

 

As a cacher how would you determine the coordinates are off if you have not located the cache?

I've seen it happen to a cache close by. Nine DNFs in a row on a 1.5D 2T.

Our GPSRs are fairly accurate and if we find that the coords may indeed be off, rather than say they are off we would log something along the lines of "Our GPSr had us about x metres from where we eventually found it after widening our search". If there was a significant discrepancy, say 10 metres or more, we would post a note or even a NM.

[+Rustynails]

Could be someone with a fancy phone instead of a real gps.

[+JesandTodd]

Could be someone with a fancy phone instead of a real gps.

 

Yawn...

[+The_Incredibles_]

Could be someone with a fancy phone instead of a real gps.

 

Yawn...

 

Double yawn. Maybe their 'fancy phones' can pickup more satellites than the 'real gps' used to hide the cache?

 

 

This is my Samsung Galaxy Note 2 picking up 18 satellites...from inside my house....

Edited February 11, 2014 by The_Incredibles_

[+Don_J]

Could be someone with a fancy phone instead of a real gps.

 

Yawn...

 

Double yawn. Maybe their 'fancy phones' can pickup more satellites than the 'real gps' used to hide the cache?

 

 

This is my Samsung Galaxy Note 2 picking up 18 satellites...from inside my house....

 

It also says that you are going 7 KPH. What's up with that? You may have a lot of satellites, but your phone thinks it's moving when it isn't. This means that the coordinates are changing as you are standing still, enough for your phone to think that you are moving. I would think that this would be problematic when trying to nail down a set of coordinates.

[+The_Incredibles_]

It also says that you are going 7 KPH. What's up with that? You may have a lot of satellites, but your phone thinks it's moving when it isn't. This means that the coordinates are changing as you are standing still, enough for your phone to think that you are moving. I would think that this would be problematic when trying to nail down a set of coordinates.

 

I'm not sure what that's about. All I know is I have been successfully finding and hiding caches with this phone since last summer.

[+RoadAndTheSky]

Often it's not the number of satellites you are receiving from, but the position of the satellites and their signal strength. I can get a better signal with just few satellites positioned on the perimeter rather than over head. As for phones verses GPS. A GPS has one function, and that is receiving signals from satellites and not however many other things they do, so I can't see a phone being any better at all.

Edited February 13, 2014 by RoadAndTheSky

[+freijn]

We updated them in hopes it will make a difference, but the question still remains: What could cause such an occurence?

 

This weekend I had something similar and think i have found the issue !! :-)

 

I complained the cache owner the coordinates were 26 meters off.

She replied that the cache have been moved 2 months ago about this distance.

She did update the cache page on this, cache page INDEED does show the correct coordinates.

 

This is what happenend.

 

If you bulk load the cache into your GPS like download a pocket Query you do get the correct coordinates.

If you do a single download like click on the page on "Send to GPS" using the webpage plugin it does fail

 

I have tested this with GC4PZ4Y.

 

I have not been able to report the bug. Anybody have a link for me?

 

Cheers,

 

Frank

[+The_Incredibles_]

Often it's not the number of satellites you are receiving from, but the position of the satellites and their signal strength. I can get a better signal with just few satellites positioned on the perimeter rather than over head. As for phones verses GPS. A GPS has one function, and that is receiving signals from satellites and not however many other things they do, so I can't see a phone being any better at all.

 

I've heard this argument before, but when you when you analyze the logic, there isn't any. It's kind of like saying so-and-so works full-time as a cook so he's better than someone who just does it as a serious hobby.

[+wmpastor]

Could be someone with a fancy phone instead of a real gps.

 

Yawn...

Right. That's beating a dead horse. That issue has been flogged to death from here to eternity and back in its own threads.

 

Those new-fangled "fancy phones" have made huge leaps forward in accuracy each year. Comparing a low-end "fancy phone" from 2008 with a high-end "fancy phone" from 2014 is like comparing a lightning bug with lightning.

[+The Jester]

Often it's not the number of satellites you are receiving from, but the position of the satellites and their signal strength. I can get a better signal with just few satellites positioned on the perimeter rather than over head. As for phones verses GPS. A GPS has one function, and that is receiving signals from satellites and not however many other things they do, so I can't see a phone being any better at all.

 

I've heard this argument before, but when you when you analyze the logic, there isn't any. It's kind of like saying so-and-so works full-time as a cook so he's better than someone who just does it as a serious hobby.

It's not really the number of satellites, it's their position that's important. The unit will use four satellites for position - best if one is overhead (time signal, very important) and three spaced around the edge. Multiple satellites help as it can choose the best four to use (as you move one or more satellites may be blocked and it will use another) but if they are all in a line across the sky you just aren't going to get a good position no matter how many are received (I've had 8 satellites in a row across and couldn't get an accuracy below 100 feet).

[+The_Incredibles_]

Often it's not the number of satellites you are receiving from, but the position of the satellites and their signal strength. I can get a better signal with just few satellites positioned on the perimeter rather than over head. As for phones verses GPS. A GPS has one function, and that is receiving signals from satellites and not however many other things they do, so I can't see a phone being any better at all.

 

I've heard this argument before, but when you when you analyze the logic, there isn't any. It's kind of like saying so-and-so works full-time as a cook so he's better than someone who just does it as a serious hobby.

It's not really the number of satellites, it's their position that's important. The unit will use four satellites for position - best if one is overhead (time signal, very important) and three spaced around the edge. Multiple satellites help as it can choose the best four to use (as you move one or more satellites may be blocked and it will use another) but if they are all in a line across the sky you just aren't going to get a good position no matter how many are received (I've had 8 satellites in a row across and couldn't get an accuracy below 100 feet).

 

I guess we have different device/experiences than. Between my Oregon 550 and my Samsung Note 2, I found the more satellites I can pick up, the more accuracy I get. Probably if I'm in a wide open area picking up lots of satellite, the signal strength would be higher overall too so maybe that's part of it.

 

I have found my devices to be so reliable and accurate, the only time I even look at the satellite display is when I'm placing a cache and generally, based on the location I'm in, I'll already know what accuracy to expect. It's pretty much guaranteed, that if I'm in a ravine or next to a tall building, I'm going to have poor accuracy and will have to put a wee bit of pink flagging up.