dubious church node

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dubious church node

John F. Eldredge
OSM Item 356845407 is a node supposedly marking the location of a church
named "Mill Creek Church", at coordinates 36.0972810, -86.7027754
<http://www.openstreetmap.org/#map=18/36.0972810/-86.7027754>. The node
history shows two changesets making edits to the node, but no changeset
for the creation of the node. It has these tags:

amenity
        place_of_worship
<http://wiki.openstreetmap.org/wiki/Tag:amenity=place%20of%20worship?uselang=en-US>

ele <http://wiki.openstreetmap.org/wiki/Key:ele?uselang=en-US> 145
gnis:county_id 037
gnis:created 05/19/1980
gnis:feature_id
<http://wiki.openstreetmap.org/wiki/Key:gnis:feature%20id?uselang=en-US>
        1306749
gnis:state_id 47
name <http://wiki.openstreetmap.org/wiki/Key:name?uselang=en-US> Mill
Creek Church
religion <http://wiki.openstreetmap.org/wiki/Key:religion?uselang=en-US>
        christian
<http://wiki.openstreetmap.org/wiki/Tag:religion=christian?uselang=en-US>

I became curious about this, as aerial photos in Google Earth do not
show a church there. I drove to these coordinates, and determined that
they are for a loading dock on the back of an industrial warehouse.
There are no signs indicating that any congregation meets there; the
warehouse appears to be in active commercial use. Should I remove this
node? -- John F. Eldredge -- [hidden email] "Darkness cannot drive
out darkness; only light can do that. Hate cannot drive out hate; only
love can do that." -- Dr. Martin Luther King, Jr.


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Re: dubious church node

Ian Dees
The history of the node shows that I created it 8 years ago:


The gnis tags indicate that it probably came in from my (somewhat misguided) GNIS import back then. If there's no recent information to corroborate the node then feel free to delete it. 

On Sep 29, 2017 18:28, "John F. Eldredge" <[hidden email]> wrote:
OSM Item 356845407 is a node supposedly marking the location of a church named "Mill Creek Church", at coordinates 36.0972810, -86.7027754 <http://www.openstreetmap.org/#map=18/36.0972810/-86.7027754>. The node history shows two changesets making edits to the node, but no changeset for the creation of the node. It has these tags:

amenity
        place_of_worship <http://wiki.openstreetmap.org/wiki/Tag:amenity=place%20of%20worship?uselang=en-US>
ele <http://wiki.openstreetmap.org/wiki/Key:ele?uselang=en-US>  145
gnis:county_id  037
gnis:created    05/19/1980
gnis:feature_id <http://wiki.openstreetmap.org/wiki/Key:gnis:feature%20id?uselang=en-US>        1306749
gnis:state_id   47
name <http://wiki.openstreetmap.org/wiki/Key:name?uselang=en-US>        Mill Creek Church
religion <http://wiki.openstreetmap.org/wiki/Key:religion?uselang=en-US>        christian <http://wiki.openstreetmap.org/wiki/Tag:religion=christian?uselang=en-US>

I became curious about this, as aerial photos in Google Earth do not show a church there. I drove to these coordinates, and determined that they are for a loading dock on the back of an industrial warehouse. There are no signs indicating that any congregation meets there; the warehouse appears to be in active commercial use. Should I remove this node? -- John F. Eldredge -- [hidden email] "Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that." -- Dr. Martin Luther King, Jr.


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Re: dubious church node

Martijn van Exel-3
If you are interested in cleaning up some of the GNIS imported features in a more structured manner, we can create a MapRoulette challenge. In fact, there is one already that we can model more of them after. Give it a try: http://maproulette.org/map/2774
Martijn

On Sep 29, 2017, at 5:33 PM, Ian Dees <[hidden email]> wrote:

The history of the node shows that I created it 8 years ago:


The gnis tags indicate that it probably came in from my (somewhat misguided) GNIS import back then. If there's no recent information to corroborate the node then feel free to delete it. 

On Sep 29, 2017 18:28, "John F. Eldredge" <[hidden email]> wrote:
OSM Item 356845407 is a node supposedly marking the location of a church named "Mill Creek Church", at coordinates 36.0972810, -86.7027754 <http://www.openstreetmap.org/#map=18/36.0972810/-86.7027754>. The node history shows two changesets making edits to the node, but no changeset for the creation of the node. It has these tags:

amenity
        place_of_worship <http://wiki.openstreetmap.org/wiki/Tag:amenity=place%20of%20worship?uselang=en-US>
ele <http://wiki.openstreetmap.org/wiki/Key:ele?uselang=en-US>  145
gnis:county_id  037
gnis:created    05/19/1980
gnis:feature_id <http://wiki.openstreetmap.org/wiki/Key:gnis:feature%20id?uselang=en-US>        1306749
gnis:state_id   47
name <http://wiki.openstreetmap.org/wiki/Key:name?uselang=en-US>        Mill Creek Church
religion <http://wiki.openstreetmap.org/wiki/Key:religion?uselang=en-US>        christian <http://wiki.openstreetmap.org/wiki/Tag:religion=christian?uselang=en-US>

I became curious about this, as aerial photos in Google Earth do not show a church there. I drove to these coordinates, and determined that they are for a loading dock on the back of an industrial warehouse. There are no signs indicating that any congregation meets there; the warehouse appears to be in active commercial use. Should I remove this node? -- John F. Eldredge -- [hidden email] "Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that." -- Dr. Martin Luther King, Jr.


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Re: dubious church node

AlaskaDave
Glad you mentioned that GNIS import, Ian.

This isn't a pressing issue but I've been doing considerable mapping in Alaska and encounter GNIS features constantly. Many of them are nodes and refer to mines, usually abandoned mines, and contain tagging that JOSM complains about, for example, using landuse=quarry on a node. Sometimes I delete that tag and add man_made=mineshaft or similar tagging but it's often not clear if the node is in the proper location. The newer, high-resolution imagery will often suggest a more likely spot for the node, and sometimes I'll move the node there, but usually it isn't obvious. There are also duplicate nodes, that is, mines having the same name but in a slightly different position and carrying a different GNIS reference number.

Can you provide some guidance about the accuracy of the positions, the duplication, and perhaps weigh in on possible tagging scenarios?

Thanks,
Dave



On Sat, Sep 30, 2017 at 6:43 AM, Martijn van Exel <[hidden email]> wrote:
If you are interested in cleaning up some of the GNIS imported features in a more structured manner, we can create a MapRoulette challenge. In fact, there is one already that we can model more of them after. Give it a try: http://maproulette.org/map/2774
Martijn

On Sep 29, 2017, at 5:33 PM, Ian Dees <[hidden email]> wrote:

The history of the node shows that I created it 8 years ago:


The gnis tags indicate that it probably came in from my (somewhat misguided) GNIS import back then. If there's no recent information to corroborate the node then feel free to delete it. 

On Sep 29, 2017 18:28, "John F. Eldredge" <[hidden email]> wrote:
OSM Item 356845407 is a node supposedly marking the location of a church named "Mill Creek Church", at coordinates 36.0972810, -86.7027754 <http://www.openstreetmap.org/#map=18/36.0972810/-86.7027754>. The node history shows two changesets making edits to the node, but no changeset for the creation of the node. It has these tags:

amenity
        place_of_worship <http://wiki.openstreetmap.org/wiki/Tag:amenity=place%20of%20worship?uselang=en-US>
ele <http://wiki.openstreetmap.org/wiki/Key:ele?uselang=en-US>  145
gnis:county_id  037
gnis:created    05/19/1980
gnis:feature_id <http://wiki.openstreetmap.org/wiki/Key:gnis:feature%20id?uselang=en-US>        1306749
gnis:state_id   47
name <http://wiki.openstreetmap.org/wiki/Key:name?uselang=en-US>        Mill Creek Church
religion <http://wiki.openstreetmap.org/wiki/Key:religion?uselang=en-US>        christian <http://wiki.openstreetmap.org/wiki/Tag:religion=christian?uselang=en-US>

I became curious about this, as aerial photos in Google Earth do not show a church there. I drove to these coordinates, and determined that they are for a loading dock on the back of an industrial warehouse. There are no signs indicating that any congregation meets there; the warehouse appears to be in active commercial use. Should I remove this node? -- John F. Eldredge -- [hidden email] "Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that." -- Dr. Martin Luther King, Jr.


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--
Dave Swarthout
Homer, Alaska
Chiang Mai, Thailand
Travel Blog at http://dswarthout.blogspot.com

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Re: dubious church node

Ed Hillsman-3
In reply to this post by John F. Eldredge
In my mapping in Albuquerque, I have come across a number of GNIS nodes tagged as churches or schools, in built-up areas, that I am unable to find on the ground anywhere near the coordinates. I’ve researched a few of them and found that they did exist at one time or another but have been demolished or incorporated into newer facilities. So I’ve added a note to these that they are “historic” but that I can’t pin down their location. Otherwise, I’ve left them alone, figuring someone with more knowledge of local history can figure out where they were located.

Ed Hillsman


> On Sep 29, 2017, at 5:26 PM, John F. Eldredge <[hidden email]> wrote:
>
> OSM Item 356845407 is a node supposedly marking the location of a church named "Mill Creek Church", at coordinates 36.0972810, -86.7027754 <http://www.openstreetmap.org/#map=18/36.0972810/-86.7027754>. The node history shows two changesets making edits to the node, but no changeset for the creation of the node. It has these tags:
>
> amenity
> place_of_worship <http://wiki.openstreetmap.org/wiki/Tag:amenity=place%20of%20worship?uselang=en-US>
> ele <http://wiki.openstreetmap.org/wiki/Key:ele?uselang=en-US> 145
> gnis:county_id 037
> gnis:created 05/19/1980
> gnis:feature_id <http://wiki.openstreetmap.org/wiki/Key:gnis:feature%20id?uselang=en-US> 1306749
> gnis:state_id 47
> name <http://wiki.openstreetmap.org/wiki/Key:name?uselang=en-US> Mill Creek Church
> religion <http://wiki.openstreetmap.org/wiki/Key:religion?uselang=en-US> christian <http://wiki.openstreetmap.org/wiki/Tag:religion=christian?uselang=en-US>
>
> I became curious about this, as aerial photos in Google Earth do not show a church there. I drove to these coordinates, and determined that they are for a loading dock on the back of an industrial warehouse. There are no signs indicating that any congregation meets there; the warehouse appears to be in active commercial use. Should I remove this node? -- John F. Eldredge -- [hidden email] "Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that." -- Dr. Martin Luther King, Jr.
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
>
>
> _______________________________________________
> Talk-us mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-us


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Re: dubious church node

max
In reply to this post by John F. Eldredge
Yeah, a Google search for "Mill Creek Church nashville" has

http://freepages.history.rootsweb.ancestry.com/~nashvillearchives/millcreek.html

as an early result. It says the church building has been dismantled
but mentions a cemetery, which still exists nearby the mislocated osm
node:

http://www.openstreetmap.org/way/53498031#map=16/36.1182/-86.7267


Max

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Re: dubious church node

EthnicFood IsGreat
In reply to this post by John F. Eldredge
> Message: 1
> Date: Fri, 29 Sep 2017 18:26:49 -0500
> From: "John F. Eldredge" <[hidden email]>
> To: OpenStreetMap Talk-US Mailing List <[hidden email]>
> Subject: [Talk-us] dubious church node
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> OSM Item 356845407 is a node supposedly marking the location of a church named
> "Mill Creek Church", at coordinates 36.0972810, -86.7027754
> <http://www.openstreetmap.org/#map=18/36.0972810/-86.7027754>. The node history
> shows two changesets making edits to the node, but no changeset for the creation of
> the node. It has these tags:
>
> amenity
> place_of_worship
> <http://wiki.openstreetmap.org/wiki/Tag:amenity=place%20of%20worship?uselang=en-
> US>
>
> ele <http://wiki.openstreetmap.org/wiki/Key:ele?uselang=en-US> 145
> gnis:county_id 037
> gnis:created 05/19/1980
> gnis:feature_id
> <http://wiki.openstreetmap.org/wiki/Key:gnis:feature%20id?uselang=en-US>
> 1306749
> gnis:state_id 47
> name <http://wiki.openstreetmap.org/wiki/Key:name?uselang=en-US> Mill
> Creek Church
> religion <http://wiki.openstreetmap.org/wiki/Key:religion?uselang=en-US>
> christian
> <http://wiki.openstreetmap.org/wiki/Tag:religion=christian?uselang=en-US>
>
> I became curious about this, as aerial photos in Google Earth do not show a church
> there. I drove to these coordinates, and determined that they are for a loading dock
> on the back of an industrial warehouse.
> There are no signs indicating that any congregation meets there; the warehouse
> appears to be in active commercial use. Should I remove this node? -- John F. Eldredge
> -- [hidden email] "Darkness cannot drive out darkness; only light can do that.
> Hate cannot drive out hate; only love can do that." -- Dr. Martin Luther King, Jr.


In the course of my mapping in the American Midwest, I have come across several small country churches of GNIS origin that no longer exist.  Often there will be a nearby cemetery, but the church facility is gone.  I simply delete the node.  In one case I know of, the church building was converted into a home, so I remapped it accordingly.

Mark


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Re: dubious church node

John F. Eldredge
In reply to this post by max
On 9/29/2017 8:31 PM, Max Erickson wrote:

> Yeah, a Google search for "Mill Creek Church nashville" has
>
> http://freepages.history.rootsweb.ancestry.com/~nashvillearchives/millcreek.html
>
> as an early result. It says the church building has been dismantled
> but mentions a cemetery, which still exists nearby the mislocated osm
> node:
>
> http://www.openstreetmap.org/way/53498031#map=16/36.1182/-86.7267
>
>
> Max
>
> _______________________________________________
> Talk-us mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-us

That sounds like a reference to the original Mill Creek Baptist Church
(there is a current-day church by that name, but it isn't descended from
the earlier church). I am the person who mapped the Mill Creek Baptist
Church Graveyard, and am a board member in a nonprofit organization,
Friends of Mill Creek Baptist Church Graveyard, Inc., that maintains the
graveyard. The Mill Creek Baptist Church was located within the
graveyard property, a couple of miles away from where this node in
question is located. It might possibly have been a different church of
some other denomination.  Before removing it, I will post a question to
a Facebook group that discusses local history, and see if anyone can
tell me if there was ever a church there.


--
John F. Eldredge -- [hidden email]
"Darkness cannot drive out darkness; only light can do that.  Hate cannot drive out hate; only love can do that." -- Dr. Martin Luther King, Jr.


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Re: dubious church node

Kevin Kenny-4
In reply to this post by Ed Hillsman-3
On Fri, Sep 29, 2017 at 8:18 PM, Ed Hillsman <[hidden email]> wrote:
In my mapping in Albuquerque, I have come across a number of GNIS nodes tagged as churches or schools, in built-up areas, that I am unable to find on the ground anywhere near the coordinates. I’ve researched a few of them and found that they did exist at one time or another but have been demolished or incorporated into newer facilities. So I’ve added a note to these that they are “historic” but that I can’t pin down their location. Otherwise, I’ve left them alone, figuring someone with more knowledge of local history can figure out where they were located.

No knowledge of local history needed. If something isn't there on the ground any more, then it shouldn't be on the map.

I feel free to delete GNIS stuff for features that no longer exist. There are cases where I've instead done things like

building=detatched historic:amenity=school

for an old schoolhouse converted to a private home.

Another point is that if you have the outline for something that GNIS shows as a node, please conflate! I've done that with a lot of buildings and parks locally - just copy-and-paste the GNIS tags from the node to the polygon and then delete the node.

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Re: dubious church node

Kevin Kenny-4
In reply to this post by EthnicFood IsGreat
On Fri, Sep 29, 2017 at 9:33 PM, Mark Bradley <[hidden email]> wrote:

In the course of my mapping in the American Midwest, I have come across several small country churches of GNIS origin that no longer exist.  Often there will be a nearby cemetery, but the church facility is gone.  I simply delete the node.  In one case I know of, the church building was converted into a home, so I remapped it accordingly.

Of course, if the cemetery is there on the ground, then it should be mapped. But deleting the node for a demolished church is entirely appropriate. For a church converted to a private home, consider:

building=detached historic:amenity=place_of_worship historic:name=* etc.

if the building still resembles a church. 

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Re: dubious church node

max
In reply to this post by John F. Eldredge
There's a fair chance that a GNIS location is off by a couple miles. A
little bit more information from GNIS is available by putting the ID
into https://geonames.usgs.gov/pls/gnispublic/

It lists "Mill Creek Baptist Church" as a variant name.

From time to time I come across a GNIS entry that is off by dozens of
miles. I figure these must be typos during the location entry or
something like that, as many of them are located well. In this case I
would assume they only knew the church was in Nashville near Mill
Creek.


Max

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Re: dubious church node

John F. Eldredge
In reply to this post by John F. Eldredge
On 9/29/2017 9:59 PM, John F. Eldredge wrote:

> On 9/29/2017 8:31 PM, Max Erickson wrote:
>> Yeah, a Google search for "Mill Creek Church nashville" has
>>
>> http://freepages.history.rootsweb.ancestry.com/~nashvillearchives/millcreek.html 
>>
>>
>> as an early result. It says the church building has been dismantled
>> but mentions a cemetery, which still exists nearby the mislocated osm
>> node:
>>
>> http://www.openstreetmap.org/way/53498031#map=16/36.1182/-86.7267
>>
>>
>> Max
>>
>> _______________________________________________
>> Talk-us mailing list
>> [hidden email]
>> https://lists.openstreetmap.org/listinfo/talk-us
>
> That sounds like a reference to the original Mill Creek Baptist Church
> (there is a current-day church by that name, but it isn't descended
> from the earlier church). I am the person who mapped the Mill Creek
> Baptist Church Graveyard, and am a board member in a nonprofit
> organization, Friends of Mill Creek Baptist Church Graveyard, Inc.,
> that maintains the graveyard. The Mill Creek Baptist Church was
> located within the graveyard property, a couple of miles away from
> where this node in question is located. It might possibly have been a
> different church of some other denomination.  Before removing it, I
> will post a question to a Facebook group that discusses local history,
> and see if anyone can tell me if there was ever a church there.
>
>
I have now learned more on a local-history Facebook group.  The location
on Antioch Pike is the original location of the Mill Creek Baptist
Church congregation that now meets on Wallace Road, about two miles
away.  This congregation is not descended from the original Mill Creek
Baptist Church, which was about two miles away in a different direction.

--
John F. Eldredge -- [hidden email]
"Darkness cannot drive out darkness; only light can do that.  Hate cannot drive out hate; only love can do that." -- Dr. Martin Luther King, Jr.


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Re: dubious church node

Mark Wagner
In reply to this post by AlaskaDave
On Sat, 30 Sep 2017 06:56:31 +0700
Dave Swarthout <[hidden email]> wrote:

> Glad you mentioned that GNIS import, Ian.
>
> This isn't a pressing issue but I've been doing considerable mapping
> in Alaska and encounter GNIS features constantly. Many of them are
> nodes and refer to mines, usually abandoned mines, and contain
> tagging that JOSM complains about, for example, using landuse=quarry
> on a node. Sometimes I delete that tag and add man_made=mineshaft or
> similar tagging but it's often not clear if the node is in the proper
> location. The newer, high-resolution imagery will often suggest a
> more likely spot for the node, and sometimes I'll move the node
> there, but usually it isn't obvious. There are also duplicate nodes,
> that is, mines having the same name but in a slightly different
> position and carrying a different GNIS reference number.
>
> Can you provide some guidance about the accuracy of the positions, the
> duplication, and perhaps weigh in on possible tagging scenarios?

In my experience, there are two common sources of position error in
GNIS:

First, many GNIS entries are pulled off of old USGS topo maps.  These
are of limited resolution, and you can't get a position more accurate
than about a city block.  It's not much of an error, but when you're
used to coordinates that will lead you to a specific door, it's
something to keep in mind.

Second, many entries have their coordinates specified using the old NAD
27 datum, but somewhere along the line, that fact was lost and the
coordinates were assumed to be in either NAD 83 or WGS 84.  This
results in an offset that increases the further you go from central
Indiana; the offset in Alaska is upwards of a hundred meters to the
west.

For churches, hospitals, post offices, and other facilities in towns,
it's not unusual for them to take the same coordinates as the center of
the town.  This mis-positioning may be combined with one or both of the
above.

The other common error you'll encounter is that the tagging is only
approximate as to type.  This is most obvious with medical facilities:
everything from doctors' offices to retirement homes gets tagged as
"amenity=hospital".  More common but less noticeable is that a wide
range of vaguely recreation-related things get tagged as "leisure=park"
-- in particular, watch out for historic markers tagged as such.

Your quarries are subject to this same type-approximation: everything
from a county road department's gravel pit to an extensive complex of
mineshafts is tagged as "landuse=quarry", as are some mining-related
industrial facilities.

--
Mark

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Re: dubious church node

AlaskaDave
"Second, many entries have their coordinates specified using the old NAD
27 datum, but somewhere along the line, that fact was lost and the
coordinates were assumed to be in either NAD 83 or WGS 84.  This
results in an offset that increases the further you go from central
Indiana; the offset in Alaska is upwards of a hundred meters to the
west."

Wow, thanks for that. If I understand what you're saying, this means many of the old GNIS nodes will be positioned about 100 meters east of where they should be? Or do I have your statement turned around?

The mine whose position I last adjusted, the Case Mine in the Chugach Mountains on the Kenai Peninsula, was quite a distance from an area of bare ground (visible only in ESRI) where an old mine site might have been. The original position was to the east of that bare area. I didn't measure the distance but will do that next time I come across such a mine.  The bare spot also happens to be where the USGS Topo places the mine, consequently, I felt moving it was justified.

I'm also guessing that the other Case Mine node,  the"duplicate" I mentioned earlier, represents perhaps a second mine_entrance on the same mining claim. However, there is nothing west of that node to provide any clue to guide a repositioning, nor does it appear on theUSGS Topo map, so I left it where it was.

On Sat, Sep 30, 2017 at 2:19 PM, Mark Wagner <[hidden email]> wrote:
On Sat, 30 Sep 2017 06:56:31 +0700
Dave Swarthout <[hidden email]> wrote:

> Glad you mentioned that GNIS import, Ian.
>
> This isn't a pressing issue but I've been doing considerable mapping
> in Alaska and encounter GNIS features constantly. Many of them are
> nodes and refer to mines, usually abandoned mines, and contain
> tagging that JOSM complains about, for example, using landuse=quarry
> on a node. Sometimes I delete that tag and add man_made=mineshaft or
> similar tagging but it's often not clear if the node is in the proper
> location. The newer, high-resolution imagery will often suggest a
> more likely spot for the node, and sometimes I'll move the node
> there, but usually it isn't obvious. There are also duplicate nodes,
> that is, mines having the same name but in a slightly different
> position and carrying a different GNIS reference number.
>
> Can you provide some guidance about the accuracy of the positions, the
> duplication, and perhaps weigh in on possible tagging scenarios?

In my experience, there are two common sources of position error in
GNIS:

First, many GNIS entries are pulled off of old USGS topo maps.  These
are of limited resolution, and you can't get a position more accurate
than about a city block.  It's not much of an error, but when you're
used to coordinates that will lead you to a specific door, it's
something to keep in mind.

Second, many entries have their coordinates specified using the old NAD
27 datum, but somewhere along the line, that fact was lost and the
coordinates were assumed to be in either NAD 83 or WGS 84.  This
results in an offset that increases the further you go from central
Indiana; the offset in Alaska is upwards of a hundred meters to the
west.

For churches, hospitals, post offices, and other facilities in towns,
it's not unusual for them to take the same coordinates as the center of
the town.  This mis-positioning may be combined with one or both of the
above.

The other common error you'll encounter is that the tagging is only
approximate as to type.  This is most obvious with medical facilities:
everything from doctors' offices to retirement homes gets tagged as
"amenity=hospital".  More common but less noticeable is that a wide
range of vaguely recreation-related things get tagged as "leisure=park"
-- in particular, watch out for historic markers tagged as such.

Your quarries are subject to this same type-approximation: everything
from a county road department's gravel pit to an extensive complex of
mineshafts is tagged as "landuse=quarry", as are some mining-related
industrial facilities.

--
Mark

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Dave Swarthout
Homer, Alaska
Chiang Mai, Thailand
Travel Blog at http://dswarthout.blogspot.com

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Re: dubious church node

Marc Gemis
In reply to this post by Kevin Kenny-4
> Another point is that if you have the outline for something that GNIS shows
> as a node, please conflate! I've done that with a lot of buildings and parks
> locally - just copy-and-paste the GNIS tags from the node to the polygon and
> then delete the node.

The utilsplugin2 [1] for JOSM and it's replace geometry is another way
to do this quickly.

m.

[1] https://wiki.openstreetmap.org/wiki/JOSM/Plugins/utilsplugin2

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Re: dubious church node

Brian May
In reply to this post by Mark Wagner
On 9/30/2017 3:19 AM, Mark Wagner wrote:
> Second, many entries have their coordinates specified using the old NAD
> 27 datum, but somewhere along the line, that fact was lost and the
> coordinates were assumed to be in either NAD 83 or WGS 84.  This
> results in an offset that increases the further you go from central
> Indiana; the offset in Alaska is upwards of a hundred meters to the
> west.
>
I found this [1] page that says:.

----

9. What datum applies to the geographic coordinates in the GNIS Database?
All coordinates in the database are in NAD 83. They were converted from
NAD 27 in September 2005.

----

And this page [2] which appears to be official metadata that doesn't
mention a datum - but it was written in 1994 (see very bottom of page).

[1] https://geonames.usgs.gov/domestic/faqs.htm
[2] https://geonames.usgs.gov/metadata.html

Brian


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Re: dubious church node

Brian May
In reply to this post by Kevin Kenny-4
On 9/29/2017 11:06 PM, Kevin Kenny wrote:
On Fri, Sep 29, 2017 at 9:33 PM, Mark Bradley <[hidden email]> wrote:

In the course of my mapping in the American Midwest, I have come across several small country churches of GNIS origin that no longer exist.  Often there will be a nearby cemetery, but the church facility is gone.  I simply delete the node.  In one case I know of, the church building was converted into a home, so I remapped it accordingly.

Of course, if the cemetery is there on the ground, then it should be mapped. But deleting the node for a demolished church is entirely appropriate. For a church converted to a private home, consider:

building=detached historic:amenity=place_of_worship historic:name=* etc.

if the building still resembles a church. 


For any arm-chair mappers out there, you cannot assume the location of the original GNIS point is accurate at all, unless you have up to date evidence it is. So if you see a church point sitting on what looks like a house in a residential neighborhood on the aerial, then either delete it,  mark it as a FIXME or leave it alone. The person working for the Feds who originally mapped the point may have been miles off.

A few thoughts:

Churches from GNIS seem to be one of the biggest "map noise" features for areas I look at. Sometimes the locational accuracy is spot on, church is still there and everything is great. Sometimes the church is a mile and half down the road on a different block. Sometimes its in the middle of the highway. Sometimes in the water, etc. When I am quickly reviewing an area and I see a church point in the water or on a road, I usually just move it to a halfway plausible location without doing more research. It would be nice to have a fairly solid process for reviewing these with external data that is of known high quality.

I did a little playing around with the new USGS Map VIewer [1] and it has a Structures layer.  This appears to be part of the volunteer corps thing w/ USGS, which was (is?) a national program to provide higher accuracy points focused on buildings and structures.  I found this [2] from 2012 that provides an overview. Looks like they intended to contribute back to OSM - but no word on that in the doc. Found this site as well [3], but out of time to dig into it for now. Anyone know more about this Structures layer?

In the USGS Map Viewer, you can click on a structure and see details about it. Some say source=centroid - to me this means parcel centroid. Many have addresses as well. The map viewer allows you to switch the base map to OSM. So then you get a nice QA tool to check OSM features in an area. The structures layer doesn't include churches, but cemeteries are included. Other features include Post Offices, State Capitol Buildings, Hospitals / Medical Centers, Police Stations, Prisons, Colleges, Technical Schools, Schools, Campgrounds, Trailheads and Visitor Information Centers.

I have a statewide parcels layer that just shows church polygons and labels that I use sometimes use as well for checking churches - others are welcome to use it if interested.

[1] https://viewer.nationalmap.gov/advanced-viewer/
[2] https://pubs.usgs.gov/of/2012/1209/pdf/ofr2012-1209.pdf
[3] https://nationalmap.gov/TheNationalMapCorps/#

Brian

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Re: dubious church node

Carl Anderson-2
​A little history on GNIS data, and the Board of Geographic Names.

The US Board of Geographic Names manages names for places and features shown on US govt maps.  They have been using a database to manage the names across maps and map scales. That database is the GNIS.

The ​original GNIS data was populated from all text labels shown on USGS maps.  The most common source was 1:24,000 scale topo quarter quads.  Text from 1:100,000, 1:250,000 and 1:1,000,000 scale maps and larger were included.

The stated map accuracy of these scales  ( https://nationalmap.gov/standards/nmas.html ) is approximately

1:24:000        40 feet
1:250,000     416 feet
1:500,000     833 feet
1:1,000,000   1666 feet

The GNIS dataset includes the most precise location for text, when the text appears on maps of different scales.

An example of the kinds of text on the maps is attached.
Inline image 1




On Sat, Sep 30, 2017 at 10:46 AM, Brian May <[hidden email]> wrote:
On 9/29/2017 11:06 PM, Kevin Kenny wrote:
On Fri, Sep 29, 2017 at 9:33 PM, Mark Bradley <[hidden email]> wrote:

In the course of my mapping in the American Midwest, I have come across several small country churches of GNIS origin that no longer exist.  Often there will be a nearby cemetery, but the church facility is gone.  I simply delete the node.  In one case I know of, the church building was converted into a home, so I remapped it accordingly.

Of course, if the cemetery is there on the ground, then it should be mapped. But deleting the node for a demolished church is entirely appropriate. For a church converted to a private home, consider:

building=detached historic:amenity=place_of_worship historic:name=* etc.

if the building still resembles a church. 


For any arm-chair mappers out there, you cannot assume the location of the original GNIS point is accurate at all, unless you have up to date evidence it is. So if you see a church point sitting on what looks like a house in a residential neighborhood on the aerial, then either delete it,  mark it as a FIXME or leave it alone. The person working for the Feds who originally mapped the point may have been miles off.

A few thoughts:

Churches from GNIS seem to be one of the biggest "map noise" features for areas I look at. Sometimes the locational accuracy is spot on, church is still there and everything is great. Sometimes the church is a mile and half down the road on a different block. Sometimes its in the middle of the highway. Sometimes in the water, etc. When I am quickly reviewing an area and I see a church point in the water or on a road, I usually just move it to a halfway plausible location without doing more research. It would be nice to have a fairly solid process for reviewing these with external data that is of known high quality.

I did a little playing around with the new USGS Map VIewer [1] and it has a Structures layer.  This appears to be part of the volunteer corps thing w/ USGS, which was (is?) a national program to provide higher accuracy points focused on buildings and structures.  I found this [2] from 2012 that provides an overview. Looks like they intended to contribute back to OSM - but no word on that in the doc. Found this site as well [3], but out of time to dig into it for now. Anyone know more about this Structures layer?

In the USGS Map Viewer, you can click on a structure and see details about it. Some say source=centroid - to me this means parcel centroid. Many have addresses as well. The map viewer allows you to switch the base map to OSM. So then you get a nice QA tool to check OSM features in an area. The structures layer doesn't include churches, but cemeteries are included. Other features include Post Offices, State Capitol Buildings, Hospitals / Medical Centers, Police Stations, Prisons, Colleges, Technical Schools, Schools, Campgrounds, Trailheads and Visitor Information Centers.

I have a statewide parcels layer that just shows church polygons and labels that I use sometimes use as well for checking churches - others are welcome to use it if interested.

[1] https://viewer.nationalmap.gov/advanced-viewer/
[2] https://pubs.usgs.gov/of/2012/1209/pdf/ofr2012-1209.pdf
[3] https://nationalmap.gov/TheNationalMapCorps/#

Brian

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Re: dubious church node

Mark Wagner
In reply to this post by AlaskaDave
On Sat, 30 Sep 2017 15:11:06 +0700
Dave Swarthout <[hidden email]> wrote:

> "Second, many entries have their coordinates specified using the old
> NAD 27 datum, but somewhere along the line, that fact was lost and the
> coordinates were assumed to be in either NAD 83 or WGS 84.  This
> results in an offset that increases the further you go from central
> Indiana; the offset in Alaska is upwards of a hundred meters to the
> west."
>
> Wow, thanks for that. If I understand what you're saying, this means
> many of the old GNIS nodes will be positioned about 100 meters east
> of where they should be? Or do I have your statement turned around?

Depending on where in the process the error was made, it could go
either way, but in my experience, the nodes are usually positioned too
far to the east.

--
Mark

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Re: dubious church node

Jesse Crawford
I also seem to have observed that, at least in rural New Mexico where I
do most of my mapping, GNIS features like historic places seem to have
only been entered to the resolution of what town they were in, and then
all ended up at something like the centroid of the town or county
limits. The result can be rather odd - before I moved them all to more
correct locations, the parking lot of a particular bank in Socorro, NM
contained over a half dozen historic homes. What an amazing place to
visit!

So this is another thing to keep in mind, it seems like the GNIS
locations may be quite a bit less granular for certain types of
features. The historic features are a good example as they were
presumably all taken from the registry and so they *do* exist, but it
can take a lot of legwork to figure out where.

--
Jesse B. Crawford

https://jbcrawford.us
[hidden email]
GPG 0x4085BDC1

On Sat, Sep 30, 2017, at 11:05 AM, Mark Wagner wrote:

> On Sat, 30 Sep 2017 15:11:06 +0700
> Dave Swarthout <[hidden email]> wrote:
>
> > "Second, many entries have their coordinates specified using the old
> > NAD 27 datum, but somewhere along the line, that fact was lost and the
> > coordinates were assumed to be in either NAD 83 or WGS 84.  This
> > results in an offset that increases the further you go from central
> > Indiana; the offset in Alaska is upwards of a hundred meters to the
> > west."
> >
> > Wow, thanks for that. If I understand what you're saying, this means
> > many of the old GNIS nodes will be positioned about 100 meters east
> > of where they should be? Or do I have your statement turned around?
>
> Depending on where in the process the error was made, it could go
> either way, but in my experience, the nodes are usually positioned too
> far to the east.
>
> --
> Mark
>
> _______________________________________________
> Talk-us mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-us

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