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Accuracy of Google sat maps


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23 minutes ago, baer2006 said:

The "clear indications of intent" can become less clear, if you don't speak the language of the cache description ;) .

That is a very good point!

 

23 minutes ago, arisoft said:

Even mystery cache needs correct coordinates for the final. Using GPS is mandatory but you can use it many ways to find the cache.

This is what I see as the problem ... In the example cache, the whole point is that you are a few feet away from six obvious potential hiding spots. I suppose the CO could list the precise coordinates of each lamppost, and the puzzle is to choose which is correct. No one in their right mind would type in the nearly identical coordinate sets, but it would satisfy the guidelines, lol. At a casual glance it might appear much more complicated than it is, but that might actually add to the intended humor.

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18 minutes ago, Doc_musketeers said:
  42 minutes ago, baer2006 said:

The "clear indications of intent" can become less clear, if you don't speak the language of the cache description ;) .

Although in my particular example, I think finding yourself a a 20’ wide grove of lampposts wouldn’t leave the average cacher too confused. (The elephant in this thread: Why did they need soo many lampposts in this one little corner of the parking lot?? It’s like one per car!)

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1 hour ago, Doc_musketeers said:

Im still curious, how do you create any sort of offset cache that might amount to 0.001’ difference in lat or long?

I have found multi-caches where I could touch the first stage with one hand while touching the final stage with the other. I think that's about a 0.001' difference in lat or long. Works for me.

1 hour ago, Doc_musketeers said:

I suppose my biggest fear is that inventive caches that don’t perfectly fit a box get shouted down instead of the community trying to create a way for them to exist. EDIT: yes, Puzzle/Mystery is a catchall ... so I guess that does work. I just look for a bit more challenge in that category than “look up from your GPSr” lol

Exactly. The point of the mystery/puzzle type being flexible is that it can serve as a catch-all type, a "staging ground for new and unique geocaches that do not fit in another category". Or maybe it's a form of multi-cache, if it's just a matter of going to the posted coordinates and figuring out the offset (however the offset is provided). But a traditional cache is "a container at the given coordinates".

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18 minutes ago, niraD said:

I have found multi-caches where I could touch the first stage with one hand while touching the final stage with the other. I think that's about a 0.001' difference in lat or long. Works for me.

Exactly. The point of the mystery/puzzle type being flexible is that it can serve as a catch-all type, a "staging ground for new and unique geocaches that do not fit in another category". Or maybe it's a form of multi-cache, if it's just a matter of going to the posted coordinates and figuring out the offset (however the offset is provided). But a traditional cache is "a container at the given coordinates".

Yep. Again I haven’t seen anyone actually too riled up about this cache (outside of this forum, lol) but I suppose if it looked like an actual issue it would be easy enough to suggest such alterations to the CO. Or as inspired by Arisofts comment, the addition of “final coordinates” could even add to the spoof.

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32 minutes ago, Doc_musketeers said:

Yep. Again I haven’t seen anyone actually too riled up about this cache (outside of this forum, lol) but I suppose if it looked like an actual issue it would be easy enough to suggest such alterations to the CO. Or as inspired by Arisofts comment, the addition of “final coordinates” could even add to the spoof.

I'm not sure anyone is or would be "too riled up" about a variation of 10ft/3m, since that is within the accuracy expected from a civilian GPS device.

But 70ft/21m, sure. I've seen locations with terrible GPS reception where that would be considered normal, and where cache owners tend to include good hints (or even letterbox-style instructions) to compensate. But in areas with normal GPS reception, that's unacceptable. And 200ft/61m is right out.

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35 minutes ago, niraD said:

I'm not sure anyone is or would be "too riled up" about a variation of 10ft/3m, since that is within the accuracy expected from a civilian GPS device.

But 70ft/21m, sure. I've seen locations with terrible GPS reception where that would be considered normal, and where cache owners tend to include good hints (or even letterbox-style instructions) to compensate. But in areas with normal GPS reception, that's unacceptable. And 200ft/61m is right out.

Yeah, I checked it out, ironically using a map app. It’s maybe 50 ft from GZ to the furthest lamppost in an otherwise empty row of parking spaces.

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I think it might help if you remember how geocaching started: as a way to get out and have fun with the newly-improved civilian GPS accuracy. The first geocaches ("stashes" at that time) were at the posted coordinates. In fact, the whole point was that the coordinates should be good enough to point right to the cache. Fast forward to today, and the "Traditional" cache type is supposed to follow this original idea: that the container is at the posted coordinates. There may be some kind of puzzle at those posted coordinates that you need to solve to sign the log, in which case a Field Puzzle attribute could be used, but the cache should still be at the posted coordinates. The cache in the middle of a bunch of lamp posts is clearly not following the intent of the Traditional cache type. As a Multi or Mystery, it may be considered to be an innovative cache, but as a Traditional it's just a cache with bad coordinates and it should be expected that finders may post better coordinates. If the owner of that cache isn't happy with finders doing that, then they should archive it and re-list it as a more appropriate cache type.

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22 minutes ago, The A-Team said:

I think it might help if you remember how geocaching started: as a way to get out and have fun with the newly-improved civilian GPS accuracy. The first geocaches ("stashes" at that time) were at the posted coordinates. In fact, the whole point was that the coordinates should be good enough to point right to the cache. Fast forward to today, and the "Traditional" cache type is supposed to follow this original idea: that the container is at the posted coordinates. There may be some kind of puzzle at those posted coordinates that you need to solve to sign the log, in which case a Field Puzzle attribute could be used, but the cache should still be at the posted coordinates. The cache in the middle of a bunch of lamp posts is clearly not following the intent of the Traditional cache type. As a Multi or Mystery, it may be considered to be an innovative cache, but as a Traditional it's just a cache with bad coordinates and it should be expected that finders may post better coordinates. If the owner of that cache isn't happy with finders doing that, then they should archive it and re-list it as a more appropriate cache type.

Yep, I was thinking about that history. Ironically, that’s all I thought there was to Geocaching for a long time. We had our Garmin for backpacking and I couldn’t figure out why anyone could get so excited about basic navigation, lol. I think I envisioned all caches as being more like a benchmark. Now I’m a bit obsessed, lol.

As for the example cache, if I was CO I think I’d follow your exact advise (and that of others) and re-list it. I have some bigger fish to fry with some local CO’s so I won’t personally tilt at this windmill (I haven’t even been to the cache) but I think if it were more of an issue I’d open communication with the CO, perhaps even a Reviewer. I still think I’d personally avoid directly posting updated coordinates, but that’s just me.

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30 minutes ago, Doc_musketeers said:

As for the example cache, if I was CO I think I’d follow your exact advise (and that of others) and re-list it. I have some bigger fish to fry with some local CO’s so I won’t personally tilt at this windmill (I haven’t even been to the cache) but I think if it were more of an issue I’d open communication with the CO, perhaps even a Reviewer. I still think I’d personally avoid directly posting updated coordinates, but that’s just me.

If the coords are deliberately off,  (or...  met a kid searching for a mystery cache.  Coords on his Iphone were 50' off from where I was searching...), or if the coords are bad, post updated coords!  Please!  I can use those to find the cache, rather than searching 50' away.  I post the updated coords.

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36 minutes ago, Harry Dolphin said:

If the coords are deliberately off,  (or...  met a kid searching for a mystery cache.  Coords on his Iphone were 50' off from where I was searching...), or if the coords are bad, post updated coords!  Please!  I can use those to find the cache, rather than searching 50' away.  I post the updated coords.

Not sure if you caught the context since this was a somewhat off-topic side plot of the original post. The coordinates for the cache we were discussing are, in the technical sense “deliberately off” as part of the premise of the cache. Consensus is it shouldn’t be listed as a Traditional, and since posting the “correct” coordinates would destroy the premise, I was saying I would suggest re listing rather than treat it like a traditional and give “correct coordinates.” In this case doing so would almost be the equivalent of walking up behind another cacher eagerly searching and saying “No, it’s the fake rock by your left foot.” The coordinates didn’t necessarily put you in the “wrong” spot to search, they put you in the middle of a “search zone” with 6 possibilities each 20’ or so away

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6 hours ago, Doc_musketeers said:

This is what I see as the problem ... In the example cache, the whole point is that you are a few feet away from six obvious potential hiding spots. I suppose the CO could list the precise coordinates of each lamppost, and the puzzle is to choose which is correct. No one in their right mind would type in the nearly identical coordinate sets, but it would satisfy the guidelines, lol. At a casual glance it might appear much more complicated than it is, but that might actually add to the intended humor.

This is a multi-cache because there is many waypoints. I have one with two waypoints (100m apart) and only one cache.

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30 minutes ago, arisoft said:

This is a multi-cache because there is many waypoints. I have one with two waypoints (100m apart) and only one cache.

Setting this up as a multi would be cumbersome. There is only one cache here as well. If considered a multi, that would make the current posted coordinates, which are on bare tarmac, the first stage. The “final stage” is less than 20m away, apparently under the skirt of a lamppost. Since there’s no way to place a physical cache at the first waypoint, the only way to lead a player to the final stage is through hints in the description. The entire point of this cache is that there are six lampposts surrounding the “first waypoint.” If the description simply listed the coordinates of the final, you wouldn’t need the first waypoint and this would be a needlessly awkward P&G LPC.

If you want to leave it to the Finder to figure out which of the 6 lampposts holds the cache, which was the actual CO’s entire point, you’d most likely need to set it up as a mystery, perhaps listing the precise coordinates of all 6 lampposts and indicating that only one of those 6 waypoints was the one where the cache would be found.

ETA: unless you are arguing that this would be a seven-stage multi where the first stage puts you in view of the next six “stages” and 5 of those would supply the clue “not here! Go to the next lamppost!” to lead you to the final?

Edited by Doc_musketeers
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2 hours ago, Doc_musketeers said:

ETA: unless you are arguing that this would be a seven-stage multi where the first stage puts you in view of the next six “stages” and 5 of those would supply the clue “not here! Go to the next lamppost!” to lead you to the final?

Of course not. It's only a six-stage multi. The posted coordinates in the middle are clearly parking coordinates, which don't count as a stage. ;)

The Monty Hall cache listed the three "door" LPCs as waypoints (Door #1, Door #2, and Door #3, or something like that). There was also a "final location" waypoint, but it wasn't shown to seekers, and it was redundant with one of the "door" LPCs.

Edited by niraD
emoji for clarity
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9 hours ago, Doc_musketeers said:

The coordinates didn’t necessarily put you in the “wrong” spot to search, they put you in the middle of a “search zone” with 6 possibilities each 20’ or so away

As niraD pointed out 10ft/3m is within the expected accuracy of civilian GPS devices. Counting together the positional error of the hiders device and yours this means a search radius of 20ft/6m. So Traditional sounds fine to me, even if you have to check six spots worst case. Typical needle in the haystack hides require more work.

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2 hours ago, Rebore said:

As niraD pointed out 10ft/3m is within the expected accuracy of civilian GPS devices. Counting together the positional error of the hiders device and yours this means a search radius of 20ft/6m. So Traditional sounds fine to me, even if you have to check six spots worst case. Typical needle in the haystack hides require more work.

That was my initial feeling too, that the coordinates were chosen to put you in a specific location from which to search within a reasonably small radius. But the argument that’s been made is that the intent of a Traditional as per Guidelines is for the container to be at the posted coordinates and that those coordinates should be as accurate as possible. The CO here is presenting intentionally fuzzy coordinates. The upshot being that some players would feel justified if not compelled to submit the “correct coordinates” to the specific lamppost and thus “spoil” the clearly described “1 of 6” concept of the hide.

this all started because I used this local cache as a humorous example of attempts at (from the perspective of the CO) unhelpful coordinate adjustment. I don’t have a nano’s worth of personal investment in this cache, lol. I think the above argument is technically correct, I just (1) don’t think I’d make it my personal mission to correct something that doesn’t affect the practical search for this cache, and (2) even if I thought it should be changed, I’d approach it in a way that recognized the CO’s hide concept and didn’t give away the challenge for which  the CO chose this hide location.

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Coincidentally, and closer to topic,  my wife and I ran into another local Geocaching couple yesterday evening. We were all hoping for FTF on a new cache placed on a narrow, abandoned RR bridge turned footbridge/fishing spot. One of them was using the sat view from the app to try to determine cache position relative to tracks, etc. We discussed how much weight they put on that image. To them it’s one more potential bit of evidence that might help them locate a pesky hide. Three of us were poking around on what appeared to be the “correct” side of the bridge based on that sat image  while my wife checked the opposite side “just in case.” Wanna guess who made the Find?

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54 minutes ago, Doc_musketeers said:

The CO here is presenting intentionally fuzzy coordinates. 

Well, I wouldn't be sure of that and I wouldn't post "corrected" coordinates within that margin of error. How do I know that my GPSr is showing more accurate coordinats if they are well within the fuzziness of our devices? Of course you could use Google maps to pinpoint the right lamppost, so other cachers using the satellite view know where to look. But that's not how the game is inteded to be played and you don't know if the coords from Google maps are more accurate - they just fit to the image.

There's a local old-school cacher in my area who is still useing the 15 year old GPSr bought back then, because it simply still works. No way that it comes near to the precision of nowadays devices.

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1 hour ago, Rebore said:

Well, I wouldn't be sure of that and I wouldn't post "corrected" coordinates within that margin of error. How do I know that my GPSr is showing more accurate coordinats if they are well within the fuzziness of our devices?

Lol. I’m not accusing the CO of posting “misleading” coordinates. It’s pretty much his stated intent. I agree that the margin of error makes trying to “fix” his cache irrelevant even if the fuzziness wasn’t intentional. 

1 hour ago, Rebore said:

Of course you could use Google maps to pinpoint the right lamppost, so other cachers using the satellite view know where to look.

You probably offered this suggestion based on the core topic of this thread. I do think that the prevalence of map navigation will influence our game going forward. For better and for worse and we all need to be aware of how other players are using these resources.

 In connection with the unintended sidebar debate about this particular cache, your suggestion is also hilariously (and no doubt unintentionally) ironic. I didn’t see an issue with this cache but a number of other forum users logically argued that it didn’t technically meet the Guidelines because the core intent is reliance on accurate GPSr usage. Most those same forum users felt strongly about reliance on GPS vs Sat Maps for creating those coordinates. So your suggestion might be akin to hiring the devil to proofread the Bible, lol.

Edited by Doc_musketeers
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21 hours ago, Doc_musketeers said:

ETA: unless you are arguing that this would be a seven-stage multi where the first stage puts you in view of the next six “stages” and 5 of those would supply the clue “not here! Go to the next lamppost!” to lead you to the final?

There is a one special rule for multi-caches. Geocacher must visit at the posted coordinates.

 

Multi-Cache Mystery Cache
Must have multiple stages May have multiple stages.
The posted coordinates must be for the first stage. The posted coordinates may be bogus coordinates, parking coordinates, or for the first or final stage.

 

This means that posted coordinates must be one of those lamp posts. It can not be parking or bogus. There are six stages and the final is one of them.

Edited by arisoft
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On 2/2/2018 at 4:05 PM, baer2006 said:

Bottom line is: I think the idea "Traditional = exactly at GZ" is a good one, and should be followed.

If you want to place a funny or tricky hide by using fuzzy coordinates, create a multi cache. The off-coordinate hide is not the final, but gives the exact(!) coordinates of the final.

Another way to desribe it would be... Anyone can create a "trick" cache by intentionally giving a false impression with the cache listing guidelines. List it as a Large, but it's actually a micro - hey that's part of the challenge!  List it as a T1 when you actually have to climb a tree - hey that's part of the challenge!  Giving false coordinates when it's expected that coordinates are accurate for a specific cache type isn't a "puzzle", it's deceptive. Like I mentioned earlier, it's not that the concept (in the given example) is a bad one, it's just not really appropriate for a Traditional cache.

Don't take the easy way out to make a hard find by misleading cachers with listing details they implicitly trust to be what they are. :)

 

On 2/2/2018 at 4:31 PM, Doc_musketeers said:

This is what I see as the problem ... In the example cache, the whole point is that you are a few feet away from six obvious potential hiding spots. I suppose the CO could list the precise coordinates of each lamppost, and the puzzle is to choose which is correct.

Well there's also this example - on one hand, we have a CO who takes a coordinate reading at the lamp post, and published it with those coordinates, intending that the coordinates are accurate to the cache location.  But they're not, and end up at best somewhere equidistant to a few other spots. On the other hand, we have a CO who intentionally provides fuzzy coordinates knowing they could get accurate coordiantes, and publishes those with the intent to make geocachers search multiple spots.

Really all we're addressing here is the intent of the CO. In the first case, if a finder posts updated coordinates for their reading, the CO isn't upset. In the latter case, the CO's "puzzle" is supposedly ruined. The finder may have no idea whether the CO intended to provide fuzzy coordinates (what if they don't read the description?).

The point is, there are many unknown factors, and generally the siding will go to the cacher for something like this. And since the intent of the Traditional is to lead a cacher to the cache, if the CO intentionally gives bad coordinates, that's against the intent, and shouldn't be done. There are of course always exceptions.  But a finder posting 'better' coordinates to a Traditional cache isn't like a finder posting the Final coordinates to a mystery/puzzle cache. Not in the slightest.

 

On 2/2/2018 at 4:54 PM, Doc_musketeers said:

the addition of “final coordinates” could even add to the spoof.

See, that would be a neat 'trick' (if a reviewer allowed it - since technically a Traditional shouldn't need a Final waypoint). Who knows though, a reviewer might publish that. But the listing itself indicates the 'trick'.

 

On 2/2/2018 at 7:11 PM, Harry Dolphin said:

If the coords are deliberately off,  (or...  met a kid searching for a mystery cache.  Coords on his Iphone were 50' off from where I was searching...), or if the coords are bad, post updated coords!  Please!  I can use those to find the cache, rather than searching 50' away.  I post the updated coords.

I've seen caches listed where the CO somehow got away with asking people to post their updated coordinates to help them with the listing coordinates.  #baffled

--

And yes, another good point.  A traditional has one waypoint (Posted=Final).  Intentionally fuzzy coordinates (let's assume beyond minimal gps accuracy afforded by 3 decimal precision DMS coordinates) make at least two waypoints - Posted, and the Final. Just by that definition alone it shouldn't be listed as a Traditional. :)

Edited by thebruce0
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57 minutes ago, thebruce0 said:

A traditional has one waypoint (Posted=Final).

Just a quibble, but I've seen traditional caches with more than one waypoint. For example, traditional caches might have parking waypoints and trailhead waypoints. But like I said, it's a quibble.

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16 hours ago, thebruce0 said:

Anyone can create a "trick" cache by intentionally giving a false impression with the cache listing guidelines. List it as a Large, but it's actually a micro - hey that's part of the challenge!  List it as a T1 when you actually have to climb a tree - hey that's part of the challenge!

While you may be able to get away with some deceptions like these (except the T1 one, which is covered by the guidelines), they wouldn't make you a very popular person. The person who came to look for the cache in order to drop some trackables or allow their child to trade swag will not be happy. You may call these "challenges", but I would call them lying in order to be unnecessarily cruel.

...and before someone brings up the old "liar caches", it's my understanding that new ones haven't been allowed for some time, so there isn't much point in discussing something that's grandfathered.

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13 minutes ago, The A-Team said:
17 hours ago, thebruce0 said:

Anyone can create a "trick" cache by intentionally giving a false impression with the cache listing guidelines. List it as a Large, but it's actually a micro - hey that's part of the challenge!  List it as a T1 when you actually have to climb a tree - hey that's part of the challenge!

While you may be able to get away with some deceptions like these (except the T1 one, which is covered by the guidelines), they wouldn't make you a very popular person. The person who came to look for the cache in order to drop some trackables or allow their child to trade swag will not be happy. You may call these "challenges", but I would call them lying in order to be unnecessarily cruel.

...and before someone brings up the old "liar caches", it's my understanding that new ones haven't been allowed for some time, so there isn't much point in discussing something that's grandfathered.

In case it was missed, I was being extremely sarcastic :P (thus: "Don't take the easy way out to make a hard find by misleading cachers with listing details they implicitly trust to be what they are.") I agree with everything you say above.  Indeed, "they wouldn't make you a very popular person."

And likely, if there are complaints, a reviewer may disable your cache to have it fixed.

As for liar caches, the only reason I think they were allowed was because the listing itself implied it was a liar cache, despite properties being entirely inaccurate - they weren't (or shouldn't have been) deceptively and intentionally falsely defined with no hint of the 'trick'.

Kind of glad liar caches aren't allowed any more anyway. I think people created them for a while when challenges were growing in popularity to provide easy DTs for rare slots.

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On 1/29/2018 at 8:26 AM, Ranger Fox said:

This burned me quite a bit when dealing with my state's reviewer.  He kept saying that some railroad tracks were too close to the coordinates I had.  I gave him the actual coordinates of the railroad tracks from my track log (put not intended) and he didn't believe me due to what the satellite maps said.  So, in the end, I went back out there and made a video to prove my cache was farther from the railroad tracks than what he was claiming.

Feel free to continue discussing guidelines for coordinates in re: cache types. It’s informative.

But I realized I’d missed something interesting waay back on page one. Ranger Fox’s experience makes me wonder how common it is for Reviewers to use online maps to get a feel for a hide? They obviously aren’t personally visiting each location so this would make sense- as long as they recognized the limitations. If it is common practice, then would it be a good preemptive move to acknowledge any “problems” that are just artifacts of the map in a reviewer note. E.g. “The railroad is not as close as it appears on Google Maps. It is actually x meters away,” or the like?

 We haven’t had anything like this happen, but we tend to be overly precise in describing details, so maybe we cover any concerns by default. Anyone else have these issues? Or was this reviewer atypical in using these maps?

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11 hours ago, Doc_musketeers said:

Feel free to continue discussing guidelines for coordinates in re: cache types. It’s informative.

But I realized I’d missed something interesting waay back on page one. Ranger Fox’s experience makes me wonder how common it is for Reviewers to use online maps to get a feel for a hide? They obviously aren’t personally visiting each location so this would make sense- as long as they recognized the limitations. If it is common practice, then would it be a good preemptive move to acknowledge any “problems” that are just artifacts of the map in a reviewer note. E.g. “The railroad is not as close as it appears on Google Maps. It is actually x meters away,” or the like? 

Or  the railroad line on the map doesn't exist any more.  It's now a rail trail.  I had a reviewer ask about one of my caches because it appear on a map to be in a farmers field.  After explaining that it was not, and who owned the property the reviewer hit the publisher button.  I suspect that reviewers commonly use maps, not to determine the specific location, but whether or not the cache may be on private property, in areas with known restrictions for geocaching, or within close proximity to railroad tracks or other sensitive areas.  It that case it doesn't have to be precise.  If the maps suggest that the cache is hidden in a general where where it shouldn't be all it takes is a confirmation from the CO that explains why it's not a prohibited location.  

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2 hours ago, NYPaddleCacher said:

I had a reviewer ask about one of my caches because it appear on a map to be in a farmers field.  After explaining that it was not, and who owned the property the reviewer hit the publisher button.

Yeah satellite imagery tends to be updated much less frequently than the road map. Out of date road maps still happen, but I find when they do they're only out of date for a couple of months tops.  Bugs me though when satellite views don't get updated for over a year. Yes, that bustling neighbourhood of settled homes does actually exist.  Reviewers shouldn't base important decisions solely on sat imagery.  Good that they trusted you :)

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20 hours ago, thebruce0 said:

Yeah satellite imagery tends to be updated much less frequently than the road map. Out of date road maps still happen, but I find when they do they're only out of date for a couple of months tops.  Bugs me though when satellite views don't get updated for over a year. Yes, that bustling neighbourhood of settled homes does actually exist.  Reviewers shouldn't base important decisions solely on sat imagery.  Good that they trusted you :)

I don't think that the reviewer used satellite imagery in this case, but I hear you.  There was a screen grab of google maps I used to use that demonstrated one of the reason why one couldn't rely on satellite photos for finding and certainly not placing a cache.  It was on a cache I found in Costa Rica in a rain forest.  The entire area for a good 20 mile radius was completely obscured by cloud cover.  In that case, the cache was located about 20 feet from a very steep 200' drop into a river so accuracy was kind of important.  It is interesting how Google addressed the cloud cover issue.  Much of the imagery is actually a stitching together of snapshots on different days, using the images which have the least amount of cloud cover, essentially creating a cloud free view of the entire globe.  Although this, and generally better resolution photos has improved satellite view significantly it is still not consistent everywhere.  There are still many places where the resolution is not so good.  There are also places where the satellite images are intentionally skewed.  Try bringing up the cache map for Beijing, zoom in on one of the parks with a lake in it, then switch between the map and satellite view.   Since satellite imagery can not produce consistent results everywhere is why I think GS won't allow them to be used for cache placement.  They can't very well say "you can use satellite imagery unless you live somewhere where the satellite imagery is not good".  Requiring the use of a GPS means that everyone everywhere is using the same method for determining lat/long coordinates.

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2 hours ago, NYPaddleCacher said:

Try bringing up the cache map for Beijing, zoom in on one of the parks with a lake in it, then switch between the map and satellite view. 

Chinese laws demand an offset between maps and satellite images, if I remember correctly. Here is a picture of Google Earth from the Hongkong border with the streets layer enabled (Hongkong requres no offset):

7f1508a9-7e60-47ef-8493-202fdb6214cd.png

ETA:

Quote

It turns out that all maps that are legally created in China must use the GCJ-02 coordinate system, which according to Wikipedia, uses an encryption algorithm that offsets the map by different amounts for different locations. Google has followed the regulations and partnered with Chinese map provider AutoNavi to obtain the data and always shows the map data using the required GCJ-02 datum.

source: GE Blog

Edited by Rebore
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As an aside, it might be interesting to know that Google isn't the only source of satellite imagery, not by a long shot.  They're just the best known.

I do a lot of editing on OpenStreetMap (which BTW is "illegal" in China; see above, heh), and much of that work is tracing features such as rivers, forest edges, etc. from imagery.  But pointedly NOT from Google's imagery; they don't allow that; we're a competitor.  But I don't think anybody misses it.  We can choose from: Bing aerial imagery, DigitalGlobe (standard or premium), ESRI World Imagery (standard or Beta-clarity), and MapBox Satellite.  And maybe even others; I haven't checked lately.  Usually I go straight to Bing and work with that; lately Bing's resolution in my area has been excellent.

And recently we've also been granted the OK to trace from Strava Heat Map, which among other things is great for calibrating the imagery we use for editing.  We're encouraged to calibrate imagery before we trace from it, which means sliding it around until the Strava dots (or GPS tracks in other forms) line up juuust right with the road/trail/etc. being displayed.

It's all pretty cool, and quite high-accuracy this way.

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