a reminder for armchair mappers

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a reminder for armchair mappers

Richard Welty-2
if you see a discrepancy between aerial imagery and OSM, before you
go adding/changing stuff, check on the history of the stuff that's there
and see if another mapper has worked on things recently (for some
value of recently.) i have done a bunch of work in the past month
adding in a new traffic circle on US 4 in Rensselaer County, NY,
using GPS traces. as part of the process,  i removed a slip ramp
from I-90 that was taken out by DOT when they built the new
circle. i just now discovered that another mapper added the slip
ramp back in, presumably because it's in the Bing imagery, which
is at this point 2 or 3 years old.

this isn't the first time i've been through this; a year or so back
a couple of armchair mappers repeatedly changed a part of Troy
to match obsolete imagery and i kept having to ask them not to
and put back in the recent changes. i now put README tags on
the ways but if i delete something i have no place to put a
README tag.

imagery goes out of date. armchair mappers must never forget
that. if the imagery doesn't match the map, contact a local mapper
if you can identify one. you could be fixing something that wasn't
actually broken.

thanks,
   richard



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Re: [Talk-us] a reminder for armchair mappers

Martijn van Exel-3
That is a great point and something I feel strongly about, having
created armchair mapper's tools like Battle Grid and Maproulette.

I will make some time to put in a warning notice into these tools that
would pop up the first time folks use it. What would a good, concise,
cautionary note look like?

On Fri, Dec 6, 2013 at 9:08 AM, Richard Welty <[hidden email]> wrote:

> if you see a discrepancy between aerial imagery and OSM, before you
> go adding/changing stuff, check on the history of the stuff that's there
> and see if another mapper has worked on things recently (for some
> value of recently.) i have done a bunch of work in the past month
> adding in a new traffic circle on US 4 in Rensselaer County, NY,
> using GPS traces. as part of the process,  i removed a slip ramp
> from I-90 that was taken out by DOT when they built the new
> circle. i just now discovered that another mapper added the slip
> ramp back in, presumably because it's in the Bing imagery, which
> is at this point 2 or 3 years old.
>
> this isn't the first time i've been through this; a year or so back
> a couple of armchair mappers repeatedly changed a part of Troy
> to match obsolete imagery and i kept having to ask them not to
> and put back in the recent changes. i now put README tags on
> the ways but if i delete something i have no place to put a
> README tag.
>
> imagery goes out of date. armchair mappers must never forget
> that. if the imagery doesn't match the map, contact a local mapper
> if you can identify one. you could be fixing something that wasn't
> actually broken.
>
> thanks,
>    richard
>
>
>
> _______________________________________________
> Talk-us mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-us
>



--
Martijn van Exel
http://oegeo.wordpress.com/
http://openstreetmap.us/

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Re: a reminder for armchair mappers

Mike N.
In reply to this post by Richard Welty-2
On 12/6/2013 11:08 AM, Richard Welty wrote:
> this isn't the first time i've been through this; a year or so back
> a couple of armchair mappers repeatedly changed a part of Troy
> to match obsolete imagery and i kept having to ask them not to
> and put back in the recent changes. i now put README tags on
> the ways but if i delete something i have no place to put a
> README tag.

  Some crazy ideas:

  highway:disused=slip_ramp
  draw a circle around the area with a note or readme


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Re: a reminder for armchair mappers

Richard Welty-2
On 12/6/13 1:30 PM, Mike N wrote:

> On 12/6/2013 11:08 AM, Richard Welty wrote:
>> this isn't the first time i've been through this; a year or so back
>> a couple of armchair mappers repeatedly changed a part of Troy
>> to match obsolete imagery and i kept having to ask them not to
>> and put back in the recent changes. i now put README tags on
>> the ways but if i delete something i have no place to put a
>> README tag.
>
>  Some crazy ideas:
>
>  highway:disused=slip_ramp
the thing is, there's no trace of the ramp left, so disused is
probably the wrong qualifier.
>  draw a circle around the area with a note or readme
i've done this before for areas which were reconstructed, it's an
approach. if you don't otherwise tag the polygon then the
rendering engines by and large ignore it.

richard



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Re: [Talk-us] a reminder for armchair mappers

Richard Welty-2
In reply to this post by Martijn van Exel-3
i'm thinking maybe we need an agreed upon way of marking these
areas so that the usual editors (id, potlatch2, josm) can flag them
as places where aerial imagery is out of date.

also, Mike N had suggested highway:disused. instead, maybe
something like highway:removed=yes would work.

i'd recommend highway:removed over highway=removed
because some rendering engines will display a line for
highway=removed, but ignore highway:removed because
they don't recognize the tag. a local mapper here in Albany
had added highway=proposed for a few proposals dating
back to the 50s and 60s that will never be built.  i changed
them to highway=unbuilt, but that didn't make them go
away, so they are now all highway:unbuilt=motorway (or
whatever.) i left them in so they didn't get put back in using
inappropriate tagging.

richard



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Re: [Talk-us] a reminder for armchair mappers

Martijn van Exel-5
Imagery is only out of date if something was (de)constructed since the
imagery was collected that would affect how that area is accurately
mapped. Therefore to me it makes more sense to tag the newer objects
rather than entire areas with a specific tag that editors would pick
up and act upon appropriately (highlight, emit a warning when you
change geometry or delete it, something like that)

On Fri, Dec 6, 2013 at 3:41 PM, Chris Lawrence <[hidden email]> wrote:

> I believe at some point there was, or at least there was discussion of
> implementing, a way to mark areas where the aerial imagery is out-of-date.
> Unfortunately I'm drawing a blank on any further development from there, but
> that would seem to be the best solution all-around (having cleaned up a
> similar issue in my area a few weeks ago).
>
>
> Chris
>
>
> On Fri, Dec 6, 2013 at 4:51 PM, Richard Welty <[hidden email]>
> wrote:
>>
>> i'm thinking maybe we need an agreed upon way of marking these
>> areas so that the usual editors (id, potlatch2, josm) can flag them
>> as places where aerial imagery is out of date.
>>
>> also, Mike N had suggested highway:disused. instead, maybe
>> something like highway:removed=yes would work.
>>
>> i'd recommend highway:removed over highway=removed
>> because some rendering engines will display a line for
>> highway=removed, but ignore highway:removed because
>> they don't recognize the tag. a local mapper here in Albany
>> had added highway=proposed for a few proposals dating
>> back to the 50s and 60s that will never be built.  i changed
>> them to highway=unbuilt, but that didn't make them go
>> away, so they are now all highway:unbuilt=motorway (or
>> whatever.) i left them in so they didn't get put back in using
>> inappropriate tagging.
>>
>> richard
>>
>>
>>
>> _______________________________________________
>> Talk-us mailing list
>> [hidden email]
>> https://lists.openstreetmap.org/listinfo/talk-us
>>
>
>
>
> --
> Chris Lawrence <[hidden email]>
>
> Website: http://www.cnlawrence.com/
>
> _______________________________________________
> Talk-us mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-us
>



--
Martijn van Exel
President, US Chapter
OpenStreetMap
http://openstreetmap.us/
http://osm.org/

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