Get the right coordinates

[+Bychowiec]

I got my first cache published yesterday and already two logs :-) But the first feedback I got was that the cache is about 15 meters of from where it´s said to be. I changed the coordinates today; went out there and took some new coordinated that I write into the cache site. But I still have a problem with it!

My husband and I were out and we both got a bit different coordinates. When I changes them today it says that I moved the coordinates by 33 meters. It was supposed to move abouy 15! 

 

I think getting the right coordinates is the hardest thing. How do I do? I tried going to the same place over and over again, I tried using different apps... 

 

I think that what makes it so hard is that it is in the middle of a forest. There are really no landmarks. 

(Geocache "The beauty of Notuddsparken" GCBOK29)

/Bychowiec

[+Max and 99]

20 meters is what I read on the log. A move of 33 meters is significant!

 

Especially since it is in the forest without a landmark you need really good coordinates!!

 

I suggest multiple readings on different days and only after letting your GPS settle down. Mine shows the accuracy at the time, using the official geocaching app. I don't even record coordinates until the accuracy is at least 15 feet. 

 

After determining the coordinates, enter them into the app and navigate back to the geocache. 

 

 

 

 

[+niraD]

2 hours ago, Bychowiec said:

I got my first cache published yesterday and already two logs :-) But the first feedback I got was that the cache is about 15 meters of from where it´s said to be. I changed the coordinates today; went out there and took some new coordinated that I write into the cache site. But I still have a problem with it!

My husband and I were out and we both got a bit different coordinates. When I changes them today it says that I moved the coordinates by 33 meters. It was supposed to move abouy 15! 

 

I think getting the right coordinates is the hardest thing. How do I do? I tried going to the same place over and over again, I tried using different apps... 

 

I think that what makes it so hard is that it is in the middle of a forest. There are really no landmarks. 

(Geocache "The beauty of Notuddsparken" GCBOK29)

/Bychowiec

If you don't trust your coordinates, then test them.
 
Enter your coordinates into your device, and then approach the cache location from at least 100ft/30m away. The arrow should point right at the cache location as you approach. Repeat the process, approaching the cache location from various directions, from at least 100ft/30m away each time. No matter which direction you approach from, the arrow should point right at the cache location.
 
If it doesn't, then adjust your coordinates until it does.
 
Bonus points for repeating the test on another day when the GPS satellites are in a different configuration.
 
Also, the Help Center article How to Get Accurate Coordinates should prove useful.

[+peter-tvm]

Do you use a mobile phone or a GPS unit like Garmin?

 

For mobile phone an app that makes averaging measurements is one way to get more precise coordinates than a single value from the app geocaching® for example. GPS point is the app I use. 

And as already said you can make measurements for 5-10 minutes on different days to see if the coordinates fluctuate.

[+lee737]

We normally check out a spot - get a coordinate while there. We normally use a GPSr to do this, but have done so with phones too. Allow it to settle - ie don't turn on and record what you see.... leave it in place for as long as possible, you'll see the reported coord home in on a value and not deviate much. 

Then when hiding the cache, redo the same - maybe even on another day if they aren't within 5m of each other. If they are around 5m, use the average of the two.

 

Then if you have to redo the coords as they are a bit off, only ever use the average of what you had, and the new one - this way hopefully you will creep in on a true, accurate coord, rather than swing from one side to the other.... which is what we see a lot do often!

 

We have rarely ever had to adjust our coords after publishing on account of coords that were reported bad - just me fine tuning a bit, ie moving by 2-3m or so..... 

[+barefootjeff]

One thing to be wary of is that, depending on your phone and the app, it may stop taking satellite readings if it thinks you aren't moving. Once you've taken your coordinates, it's a good idea to walk well away from it then return to see if it brings you back to the same place, and preferably do that in various directions. Also, as lee737 suggested, it's also a good idea to take readings on different days when the satellite constellation will be different. When I'm planning a new cache, I take readings while sussing out the area and then confirm them when I return a few days later to place the cache, and if there's a significant discrepency I'll make multiple visits and average the most likely coordinates.

 

I don't know if any phone apps do this, but my Garmin records a track of where it's gone so, standing at GZ for twenty or thirty minutes, I see its "drunken bee dance" and will move the coordinates I've taken to the centre of that.

[+The_Jumping_Pig]

On caches that are urban, I get perfect coords from sattelite view.

On forest caches, I just let my phone GPS settle until it's within 10 or so ft. Sometimes if it's gone mad I pace back and forth and get an average. But I've never spent 20-30 minutes at my cache site or visited it multiple times before hiding (although I admire those who do that. Most of my hides aren't special and involve more than one visit, I put my effort into puzzles  ).

[+hzoi]

20 hours ago, The_Jumping_Pig said:

On caches that are urban, I get perfect coords from sattelite view.

 

That method presumes that the sat view and the actual coordinates line up. They don't always.

[+barefootjeff]

2 hours ago, hzoi said:

23 hours ago, The_Jumping_Pig said:

On caches that are urban, I get perfect coords from sattelite view.

 

That method presumes that the sat view and the actual coordinates line up. They don't always.

 

Indeed. Here's some of Google Earth's "perfect" satellite images of the starting point for a recent multi I placed, using their historical image tool (all these are within the last decade):

 

 

The waypoint is supposed to be at the top of the steps, but one has it over the water and another has it in the middle of the road. The spread is about 5 metres (15 feet), so not too bad in this instance, but I've seen much worse examples at tile boundaries where whatever algorithm they used for aligning the tiles got it badly wrong. In this case it's a virtual waypoint and there's nothing to find there apart from the steps themselves, so no-ones likely to go looking in the water or on the road.

[+lee737]

On 11/25/2024 at 12:10 PM, The_Jumping_Pig said:

On caches that are urban, I get perfect coords from sattelite view.

I only ever use satellite view as a check. Devices for coords.... then before submitting, do a reality check on the main map. Of course the site doesn't let you see your new cache on the main map with satellite does it..... I have a couple of remote caches that I update the coords on to check what my new cache looks like on the main map....

[+Weber_and_Sons]

I just click on any cache near by, hit navigate, press the compass button and at the bottom it will tell you your current coordinates, then go to your geocache put the phone on top and take some screenshots of the coordinates your at and use those.

[+Bychowiec]

Ok, so I have learned a lot. I published the cache first, then I checked my coordinates and they were about 15 meters of in a direction. After changing the coordinates Im of even more in another direction. I guess I have to unpublish the geocache and the try to make it right and go back to try again. Im using my own phone, and my husbands as comparison. Feels hopmeless. 

/Bychowiec

[Pup Patrol]

6 minutes ago, Bychowiec said:

Ok, so I have learned a lot. I published the cache first, then I checked my coordinates and they were about 15 meters of in a direction. After changing the coordinates Im of even more in another direction. I guess I have to unpublish the geocache and the try to make it right and go back to try again. Im using my own phone, and my husbands as comparison. Feels hopmeless. 

/Bychowiec

 

Go to your cache page and edit the coordinates following these instructions:

 

https://www.geocaching.com/help/index.php?pg=kb.chapter&id=38&pgid=201

 

You will find lots of important information in the Knowledge Books:

https://www.geocaching.com/help/index.php

 

Pup Patrol

Edited December 3, 2024 by Pup Patrol

[+Bychowiec]

12 minutes ago, Pup Patrol said:

 

Go to your cache page and edit the coordinates following these instructions:

 

https://www.geocaching.com/help/index.php?pg=kb.chapter&id=38&pgid=201

 

You will find lots of important information in the Knowledge Books:

https://www.geocaching.com/help/index.php

 

Pup Patrol

I have edited them once like this, how many times can I do this without being seen as a bad cache owner?

/Bychowiec

[+Max and 99]

3 hours ago, Bychowiec said:

I have edited them once like this, how many times can I do this without being seen as a bad cache owner?

/Bychowiec

Better to have too many adjustments than a cache with bad coordinates that people can't find. Just my opinion. 

[+The_Jumping_Pig]

On 12/3/2024 at 3:08 PM, Bychowiec said:

I have edited them once like this, how many times can I do this without being seen as a bad cache owner?

This is your first hide. Completely expected that you will have issues. It's good to see that you are actually addressing them instead of just leaving them out there, as Max and 99 said.

 

Also: Can you delete the previous change coordinates logs besides the most recent one? (I honestly don't know)

[+The_Jumping_Pig]

On 11/25/2024 at 5:10 PM, hzoi said:

That method presumes that the sat view and the actual coordinates line up. They don't always.

Learn something new every day. Thought google did something magic to make it line up. I'll start taking readings at urban locations some crazy mislineup happens, but overall I still think that perfect sat view coords are better even if the actual coords are 10 or so ft off. I often find urban caches based off sattelite view, and I think that seeing that a cache is right on top of that bush or that tree is better than having your GPS point right to it, especially because its hard to get GPS accuracy to less than 10ft. My caches using sattelite view get comments about their spot-on coordinates that I do not see with caches that I get coordinates with using my phone...

[+barefootjeff]

3 hours ago, The_Jumping_Pig said:

I often find urban caches based off sattelite view, and I think that seeing that a cache is right on top of that bush or that tree is better than having your GPS point right to it, especially because its hard to get GPS accuracy to less than 10ft. My caches using sattelite view get comments about their spot-on coordinates that I do not see with caches that I get coordinates with using my phone...

 

That might be fine while that satellite image is current, but in a year or two (or even less in urban areas) when Google update their satellite image, you could easily find your cache 5, 10 or more metres away from that bush or tree. Here's a series of Google Earth images for one of my Adventure Lab waypoints. The waypoint is supposed to be near the top right corner of the lookout platform (shown with a red arrow in each image) but the spread on where it thinks my coordinates are is of the order of 10 metres (it's about 15 metres off in the 2010 image).

 

 

 

I took the coordinates on my Garmin and, when plugged into the AL waypoint, my phone running the app showed close enough to zero metres at the right spot. If I'd relied on the satellite image I'd have probably sent people down off the edge of the cliff or back along the track looking for the answer to the question.

Edited December 5, 2024 by barefootjeff

[+CAVinoGal]

On 11/26/2024 at 12:14 PM, lee737 said:

I only ever use satellite view as a check. Devices for coords.... then before submitting, do a reality check on the main map.

 

Same here, in fact, my process for getting coordinates is pretty much the same as lee737.  Use GPS and/or phone when checking out a location, reconfirm when placing the cache, then check the satellite view before submitting, realizing it may be off from reality.  I DO use the satellite view when seeking caches to see (maybe) which side of a building or street it may be located, and even then it's not always accurate.  When you are in the woods, satellite view is almost useless!!

[+edexter]

"Accurate cordinates" are a relative statement.  Any handheld GPSr (or app running on a phone) reading is going to depend on a number of factors:  The unit reading the coorindates, the weather, the tree cover, the number of averaged measurements, the GPSr chip set, the number of satellites in range and their arrangement in the sky.  If you set down your GPSr in the middle of an open field under perfet conditions you will get an "exploding star shape" showing your position dancing around a central point and an "average reading" somewhere near the center.  Rather than try for a "perfect reading" which won't match the next guy's reading anyway, take an averaged reading, and if you actually want to help folks locate you cache, use a location hint.  By location hint I don't mean "tree" in the middle of the woods but something that narrows the search area down to a reasonable size.  Garmin's website assets that; "

Garmin® GPS receivers are accurate to within 15 meters (49 feet) 95% of the time. Generally, users will see accuracy within 5 to 10 meters (16 to 33 feet) under normal conditions."  So that means even with two recievers matching the coordinates exactly you are still left searching a 16-33 foot radius.  Use a hint...Even simple hints like "classic hide" (on the ground, so look there), "eye high" (narrows the search area by 90 percent) "cedar" (eliminates all other trees") are helpful.  On the other hand, if your goal is to make the find difficult (d4, d5) accurate coords will spoil your fun...

[+niraD]

9 hours ago, edexter said:

Use a hint...Even simple hints like [...] "cedar" (eliminates all other trees") are helpful.

Unless the CO (or seeker) doesn't know the difference between a cedar and a juniper. Or between a cedar and a spruce. Or...

 

9 hours ago, edexter said:

On the other hand, if your goal is to make the find difficult (d4, d5) accurate coords will spoil your fun...

Nonsense. Inaccurate coordinates don't make the find more difficult. They make seekers look in the wrong place. Those are very different things.

 

A truly difficult hide is difficult even with perfectly accurate coordinates.

[+arisoft]

13 hours ago, edexter said:

On the other hand, if your goal is to make the find difficult (d4, d5) accurate coords will spoil your fun...

 

If coordinates are significantly off, I will disclose my coordinates in the log.

[+hzoi]

On 12/8/2024 at 12:49 PM, edexter said:

On the other hand, if your goal is to make the find difficult (d4, d5) accurate coords will spoil your fun...

 

Hopefully the "..." means you're kidding.

 

If not, the guidelines require accurate coordinates - they literally just say "Get accurate GPS coordinates" - and intentional inaccuracy in an attempt to increase the difficulty is frowned upon in this establishment.

[+edexter]

Well, maybe I'm kidding a little.  I have two observations based on experience:  1, Coordinate accuracy is always relative and some folks take more trouble to be as accurate as possible than others.  Overall accuracy is generally good within the limits of the equipment we use.  2, Folks who post what turn out to be "inaccurate coordinates" intentionally or not very seldom update or correct them once the cache is published.   When I can't find a regular sized cache after a diligent search, I will scan the prior logs and a quarter of the time find one or more folks who listed the coords where they found the cache.  Even more common are comments like "coords are 30 feet off to the west".   The odds of the CO then actually updating, correcting, or commenting on bad coordinates are about 1 in ten.   The half dozen times I've written to the CO, described the situation as needing some improvement and asked them to correct them, I've never heard back (though once the coords were corrected without any response).  In the great majority of cases where the bad coords remain uncorrected there seem to me to be only two possible reasons:  They aren't aware of the issue because they aren't paying attention their cache or they are and "don't care".  The folks whose "goal is to make the find difficult" may belong in either or both of those groups.  

[+edexter]

Re:  niraD's comments:

1,"Unless the CO (or seeker) doesn't know the difference between a cedar and a juniper. Or between a cedar and a spruce. Or... "

True.  A failure to understand to interpret the hint correctly is of little help.

2."Nonsense. Inaccurate coordinates don't make the find more difficult. They make seekers look in the wrong place. Those are very different things."  You are missing the obvious.  If you are looking in the wrong place due to inaccurate coordinates the find is impossible.  The reason I believe location hints are necessary for small intentionally difficult to find caches is based on the reality that there is no way to distinguish between a cache you can't find due to "bad coords" and one you can find for all other possible reasons.  

3, "A truly difficult hide is difficult even with perfectly accurate coordinates."  Yes, exactly.   Hence the need for highly accurate coordinates or a location hint for high difficulty caches as otherwise the search is pointless.  You can never find what isn't "there".  Expanding the search area is about all you can do.  But the CO can narrow the search area by any number of ways starting with "good coords".  

 

 

[+Goldenwattle]

3 hours ago, edexter said:

Well, maybe I'm kidding a little.  I have two observations based on experience:  1, Coordinate accuracy is always relative and some folks take more trouble to be as accurate as possible than others.  Overall accuracy is generally good within the limits of the equipment we use.  2, Folks who post what turn out to be "inaccurate coordinates" intentionally or not very seldom update or correct them once the cache is published.   When I can't find a regular sized cache after a diligent search, I will scan the prior logs and a quarter of the time find one or more folks who listed the coords where they found the cache.  Even more common are comments like "coords are 30 feet off to the west".   The odds of the CO then actually updating, correcting, or commenting on bad coordinates are about 1 in ten.   The half dozen times I've written to the CO, described the situation as needing some improvement and asked them to correct them, I've never heard back (though once the coords were corrected without any response).  In the great majority of cases where the bad coords remain uncorrected there seem to me to be only two possible reasons:  They aren't aware of the issue because they aren't paying attention their cache or they are and "don't care".  The folks whose "goal is to make the find difficult" may belong in either or both of those groups.  

Time for NM, and then if it's bad enough NA. Some reviewers do take this seriously.

[+barefootjeff]

4 hours ago, edexter said:

1, Coordinate accuracy is always relative and some folks take more trouble to be as accurate as possible than others.  Overall accuracy is generally good within the limits of the equipment we use.

 

Then there are some locations where it's just difficult or impossible to get accurate coordinates. A couple of weeks ago, I was sussing out a location for a new cache, a multi themed on a bronze statue along a ridge-top walking trail. At the first location I considered, maybe ten metres down the slope from the ridge-top, my GPSr, a Garmin GPSMAP 67,  just didn't want to settle, it kept wandering around over a 5 to 10 metre radius. I then went off further along the trail, looking for other potential hiding places, and returned to that original spot an hour or so later but it was still much the same with it not wanting to settle. I ultimately found a better hiding spot a bit further up the slope, with the Garmin a lot happier there too. Out of interest, when placing the container the following day, I took my old Oregon 700 along too, comparing it to the 67. I'd expect the 67 to do better, with its multi-satellite multi-band operation compared to the 700's single-satellite single-band, and that did indeed prove to be the case. At my final location, the 67 was consistently showing within a couple of metres of the coordinates I'd taken the previous day, while the 700 was wandering over about a 5 metre radius but still averaging at around the same spot.

 

Another of my recent caches is alongside a pond adjoining a tidal lake and even though it's flat ground with a 360 degree view of the sky, I get different coordinates every time I go there, with a spread of about 5 metres or so. I'm wondering whether there are signal reflections off the lake that vary with the tide; if it was closer to home I'd do some more experimentation to see if that's the case. After a couple of early finders mentioned in their logs that their device directed them to the wrong side of the pond, I made the hint a bit more explicit.

 

My worst experience was with a cache I'd placed at the base of a waterfall in a steep gully, where I was getting a spread of some 20 metres in the coordinates I took on multiple days over the course of a week. In the end all I could do was make the hint very explicit and put a spoiler photo on the cache page as well.

[+Goldenwattle]

34 minutes ago, barefootjeff said:

Then there are some locations where it's just difficult or impossible to get accurate coordinates.

Those need detailed hints.

[+niraD]

1 hour ago, barefootjeff said:

My worst experience was with a cache I'd placed at the base of a waterfall in a steep gully, where I was getting a spread of some 20 metres in the coordinates I took on multiple days over the course of a week. In the end all I could do was make the hint very explicit and put a spoiler photo on the cache page as well.

I've found a couple like that, where the CO stated that the EPE reported by his GPSr was 100ft (30m), or even more. One had an explicit hint that narrowed down GZ. The other had an in-theme narrative description of the route from the trailhead to GZ, similar to a few of the LBH caches that I've done.

[+niraD]

1 hour ago, barefootjeff said:

Another of my recent caches is alongside a pond adjoining a tidal lake and even though it's flat ground with a 360 degree view of the sky, I get different coordinates every time I go there, with a spread of about 5 metres or so.

I found one on the top of a grassy hill where we couldn't see anything at GZ. Then we read the logs that said that they found the cache 60ft (18m) from GZ. Sure enough, we found the cache about 60ft from our GZ.

 

The weird thing is that when I took coordinates so I could report the correct location, I ended up with virtually the same coordinates as the posted coordinates (one digit off, a difference of 6ft at most). I'd seen that kind of thing in steep canyons surrounded by cliffs, and in urban settings surrounded by tall buildings, but never on a grassy hill with a clear 360° view of the sky.

[+barefootjeff]

I just came across this good example of the sort of errors that can occur in the satellite image alignment. This is on the Princes Highway near Nowra on the New South Wales south coast:

 

 

The error here is about 10 metres (30 feet).

[+ecanderson]

@barefootjeff

Sorry to see you're still dealing with that sort of thing there.

 

I see that's supposed to be 2025 Airbus image data, but it's probably NOT. 

Check Google Earth instead of Google Maps.  You'll see exactly the same images (you can tell from what's on the ground in the way of vehicles, etc.) and you'll get a proper source and date for your images.

 

Actually ... looking at your image, I'm unclear just what GUI you used to pull that up.  It's got the bogus image source/date of maps.google.com, but it doesn't have the appearance of a regular maps.google.com screen shot, nor that of a Google Earth screen shot.

 

Would be interested in the coordinates for that glitch, too!

[+barefootjeff]

3 hours ago, ecanderson said:

I see that's supposed to be 2025 Airbus image data, but it's probably NOT. 

Check Google Earth instead of Google Maps.  You'll see exactly the same images (you can tell from what's on the ground in the way of vehicles, etc.) and you'll get a proper source and date for your images.

 

Here's what Google Earth shows:

 

 

 

 

3 hours ago, ecanderson said:

Actually ... looking at your image, I'm unclear just what GUI you used to pull that up.  It's got the bogus image source/date of maps.google.com, but it doesn't have the appearance of a regular maps.google.com screen shot, nor that of a Google Earth screen shot.

 

It was from the satellite view on the geocaching.com Browse map.

 

3 hours ago, ecanderson said:

Would be interested in the coordinates for that glitch, too!

 

S 34° 50.025 E 150° 35.795.

[+Goldenwattle]

7 minutes ago, barefootjeff said:

S 34° 50.025 E 150° 35.795.

I also see that on Google, but not on the geocaching map.

[+killyman1]

Have you your phone in a case that has a magnetic clasp ? I found this can cause the coordinates to jump about.

[+ecanderson]

On 1/18/2025 at 6:12 PM, barefootjeff said:

 

Here's what Google Earth shows:

 

 

 

 

 

It was from the satellite view on the geocaching.com Browse map.

 

 

S 34° 50.025 E 150° 35.795.

Fascinating.  Using GE, while I see the error right where you call it, I note no 'lateral' shift when looking either east or west of that location.  Wonder why / how the error is isolated to such a small area? 

 

Can you see this anywhere else in the vicinity?  I can't see it.

[+ChriBli]

On 1/20/2025 at 6:52 PM, ecanderson said:

Fascinating.  Using GE, while I see the error right where you call it, I note no 'lateral' shift when looking either east or west of that location.  Wonder why / how the error is isolated to such a small area? 

 

Can you see this anywhere else in the vicinity?  I can't see it.

 

An even bigger problem seems to be the poor alignment between map and satellite data in that area. I were to get coordinates from each to the center of this roundabout there would be a 25 m difference.

 

Might there be some fancy algorithm to match adjoining satellite photos to each other using features like roads etc, to avoid visible seams? And that algorithm being thrown off by this unusual and sudden change of shoulder width of that road just there?

[+hzoi]

On 1/19/2025 at 4:29 PM, killyman1 said:

Have you your phone in a case that has a magnetic clasp ? I found this can cause the coordinates to jump about.

 

GPS location works on receiving radio signals. Magnets should not affect this process. This thread from 2002 is as true now as it was then.