[Imports] Address import from city government source

Thu Aug 4 00:04:44 UTC 2022

Hello again Joe,

I went to your city's website and found the address data I believe you are
interested in having in OSM[0].  Probably the first thing is to get a clear
official statement as to the license,  Currently the data has this
"license":
GIS information is not adequate for legal boundary definition. The
information depicted on GIS maps is for general planning purposes only and
should not be used for legal boundary definition, regulatory
interpretation, or property conveyance purposes.

Data and information is provided by the GIS system with the understanding
that it is not guaranteed to be correct or complete. All data is subject to
change with periodic updates. The City of Castle Pines makes no claims,
representations or warranties, express or implied, concerning the validity,
reliability or the accuracy of the GIS data and GIS data products furnished
by the City, specifically including the implied or expressed validity of
any uses of such data.

I am not a legal expert, but this seems to be more of a disclaimer rather
than a license.  This page on the OSM wiki shows which common licenses are
compatible with ODBL[1].  Also, it seems the data was taken from Douglas
County, and if they are the true data owner, then we probably should engage
them in this discussion.   Alternatively, a letter signed by an authorized
person in the city (or county if they are the data owner) explicitly giving
permission for the data to be imported into OSM could work.  Suggested
templates are here[2]. Is your city a member of DRCOG?  DRCOG has worked
with OSM before.

I was unable to find a dataset on your website for your city's boundary,
although I could probably just dissolve all of the parcel data.  Once that
data is available with an appropriate license making the necessary boundary
edits in OSM should be relatively easy.  OSM uses "relations" for
boundaries such that the boundary between two cities (e.g.) is only
represented once.  This prevents any "no man's land" in the data, but it is
a concept that may be foreign to someone coming from a GIS/OGC simple
features background.

Mike

[0]
https://cp-public-info-castlepines.hub.arcgis.com/datasets/castlepines::address-points-with-use-code/explore?location=39.471247%2C-104.883243%2C14.89
[1] https://wiki.openstreetmap.org/wiki/Import/ODbL_Compatibility
[2] https://wiki.openstreetmap.org/wiki/Import/Getting_permission

On Tue, Aug 2, 2022 at 5:14 PM Mike Thompson <miketho16 at gmail.com> wrote:

>
>
> On Tue, Aug 2, 2022 at 5:02 PM Greg Troxel <gdt at lexort.com> wrote:
>
>>
>> Joe Rhodes <joe.rhodes at castlepinesco.gov> writes:
>>
>> > I'm the GIS manager for the newest municipality in the State of
>> > Colorado, City of Castle Pines.
>>
>> Welcome to OSM.
>>
> Yes, welcome to OSM!
>
> I am in Colorado and an experienced mapper.  I can help, but you will need
> to deal with the license issue, and some of the other things Greg mentions
> (good advice from Greg all around, which I second).
>
> Mike
>
>
>>
>> I don't know if you have experience editing OSM (not doing an import,
>> just normal mapper activity).  Generally, I and I think most others see
>> that as a prereq.
>>
>> Have you read:
>>
>>   https://wiki.openstreetmap.org/wiki/Import/Guidelines
>>
>> You'll have to prepare documentation.  One of the harder parts will be
>> conflation with existing data.
>>
>> The easy part, to get one of the showstoppers out of the way:
>>
>>   Please provide a link to download the data (no login, that anybody can
>>   do).
>>
>>   Please provide a link to a public statement of the license for the
>>   data, so that we can see if it meets the OSM requirements.
>>
>>   Are you in touch with the mappers that have edited in your area?  Have
>>   you discussed this with them?  What do they think?  If not, please
>>   find them.
>>
>> > Many addresses in our city are missing
>> > from OSM, and the ones that are there do not show Castle Pines as the
>> > city (they appear to just be in unincorporated Douglas County). I am
>> > seeking approval to do an import of the full set of address points for
>> > our city in order to correct these problems.
>>
>> "import the full set" and "many are missing" do not go together.  You'll
>> need a conflation process -- which I think should be one with published,
>> open-source code, so others in the community can replicate it -- that
>> looks at your address data and matches it with OSM data, more or less
>> sorting it into "address match, close geographically", "address match,
>> far off", and "address not in OSM".  The middle category needs manual
>> review (that doesn't solidly presume either db is right) and the third
>> is what ends up proceeding in import.  Then there's the question of what
>> object it is attached too, or just a bare point with address tags.
>>
>> > In addition, the city boundary is incorrect in OSM. The city has a
>> > multipart boundary (there are two non-contiguous sections on each side
>> > of an interstate highway), and only the eastern portion shows on
>> > OSM. Because it is non-contiguous/multipart, I am unable to edit it to
>> > reflect the correct boundary, so I'm seeking approval to import the
>> > correct boundary as well.
>>
>> I don't understand how you can't edit it.  Have you asked the local
>> mappers for help?
>>
>> It sounds like it should be a multipolygon.  You say "shows on OSM" but
>> we should be talking about the objects in the database, not the output
>> of any render.  Let's assume there is a single closed way which is one
>> of the parts and it has the admin/name tags.  The first thing to do is
>> look at the history (^H in JOSM, and if you haven't learned JOSM I would
>> recommend that before importing, because if you import anything you have
>> bit off the repsonsibility to fix any problems) and contact the people
>> that edited it before and talk about the situation.
>>
>> If what you want to do is take a polygon for the missing half -- after
>> verifying it really is missing -- and convert that to osm and turn the
>> existing closed way and the new one into a multipolygon, then that's not
>> that big a deal, but given that you seem to be new I think the steps of
>> community consultation, public data, license, transform mechanism should
>> be written down.
>>
>> You didn't talk about the half that is there being wrong, so I'm
>> assuming you don't wnat to change that.  In general "my data is better,
>> and so I want to delete and add mine" is not ok; OSM has a strong
>> doctrine of deference to hand mapping, even if any particular thing that
>> is actually wrong can be fixed.  Sometimes OSM people have good data
>> about boundaries and it can be better than the official data.  As an
>> example I've measured my town's boundary stones with RTK, and the
>> official data is an 1890 survey in the New England datum reckoned
>> forward to NAD27 and then NAD83.  The amazing thing is that we agree at
>> the 0.5m level, and I may this year get to the point where I can
>> reasonably confidently say my values are better.  But most OSM data is
>> not like this.
>>
>> Finally, and this is not a big deal, but I'm guessing your data is in
>> NAD83(2011) epoch 2010.0 and OSM is nominally in WGS84.  That's fuzzy,
>> but you should transform to the latest realization, WGS84(G2159), or
>> something like ITRF2014 as a close proxy.
>>
>> Greg (osm user gdt)
>> _______________________________________________
>> Imports mailing list
>> Imports at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/imports
>>
>
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