Re: [Talk-us] Unintentional improvements in OSM data influencing / improving other databases

[Kevin Kenny]

On Wed, Sep 2, 2020 at 2:48 PM Joseph Eisenberg 
wrote:

> But if we are talking about legal parcel boundaries or legal protected
> area boundaries, or administrative limits, then it's not at all possible
> for OpenStreetMap users to resolve these conflicts in our database alone.
>
> What needs to happen is bringing this information back to the local
> government and asking them to correct the data and provide an
> authoritative, public-domain source for everyone to use.
>
> It's no good if OpenStreetMap has a more "accurate" boundary line which
> follows a physical feature like a ridgeline, if the legal definition is
> different. Determining this might require lawyers getting involved.
>
> Now certainly OpenStreetMap data, which can include features like
> ridgelines, waterways, roads and paths, which are often used to determine
> historic land ownership boundaries, can be useful in determining if
> existing databases are accurate and precise. But unless those outside
> databases are corrected, our data will be inaccurate as well, when it comes
> to legal issues like boundaries.
>

You are labouring under a misconception that there is some authoritative
database somewhere in the halls of government. There simply is not.

In the US legal system, the verbal description of a property in a deed
takes absolute precedence over any map, and the witness marks in the field
*are* the boundary. Recovering and refreshing the marks is a big part of
what a land surveyor does.

If there is a dispute over a boundary,  the courts can resolve it. In the
cases we're talking about, the courts will not weigh in because there is no
case or controversy before them.

In no case is _any_ government GIS system in most states[1] of the US an
authoritative reference for a property line, and there is nothing
resembling a Torrens title system. Even in the ten or so states that
maintain a registry of land plans as well as titles, the verbal description
generally takes priority over the map. The registries are more about
identifying parcels, and tracking who owns them (and holds easements,
liens, deeds of trust, and the like) than they are about specifying the
metes and bounds of the parcels.

One reason that my uncle's feud with his neighbour could go on so long was
that the formal description of the property was something like 'SW/4 of
NW/4 of Section XX, Lot YY, Great Lot ZZ, Division 1 of the Minisink Patent
of 1704.  Searching that sort of title is like writing _Roots_!
Fortunately, when my brother and the neighbour decided to bury the hatchet,
a forester with a metal detector was able to recover not only corner
monuments, but the remains of a barbed-wire fence - so there was an obvious
place to strike the line.

Even for public land, there's no single authoritative source.  In New York,
for instance, there was a legal dispute about land ownership between
private landholders and the state that went back to the 1860s that required
a statewide constitutional referendum in 2013 to authorize the settlement.
https://www.wamc.org/post/new-york-settles-adirondack-land-dispute . (Yes,
the place is named 'Township 40'.) When this sort of title dispute can
languish for 150 years, how could there be an authoritative reference?

There are cases where I've left inconsistent boundaries in OSM
intentionally. In at least one of those places, I successfully recovered
monuments at both of the inconsistent corners. That one's beyond my pay
grade and will be an issue for the courts if there's ever a dispute.
(Unlikely, both sides of the line are protected forest land, belonging to
different authorities.)

In typically American-capitalist fashion, in lieu of state registration, we
have a privatized system of title insurance
.

[Notes]

[1] There's limited Torrens title in Colorado, Georgia, Hawaii, Illinois,
Massachusetts, Minnesota, New York, North Carolina, Ohio and Washington.
Several of these states are in the process of abolishing it.

In New York, Torrens title was abolished in 2000, and there have been no
new land title registrations since. Even before then, it was optional,
complex and expensive. (I bought my house in 1993 and got a warranty deed,
not a certificate of registered title.) There are still some landowners
still have a Certificate of Title rather than a deed. There are only a
handful of Torrens properties in most counties. It is most common in
Suffolk County, and there are several in Kings and Rockland counties. It's
now considered rather a blemish; many title insurers won't accept a
certificate of title and need to do an extended search to protect against
claims of fraud against the certified title. It's a mess.

Illinois has abolished its Torrens system entirely, but again, there are
issues surrounding legacy title, so the registry must remain accessible.

Torrens title has been unpopular because it is vulnerable to fraudulent
deeds and has been abused

Re: [Talk-us] Unintentional improvements in OSM data influencing / improving other databases

[Joseph Eisenberg]

RE: "Many government and agency data sources are in conflict with each
other over the same information; OSM can serve to provide "resolved"
versions that are confirmed with ground observation where required."

Similar thoughts have been expressed previously in this thread.

But if we are talking about legal parcel boundaries or legal protected area
boundaries, or administrative limits, then it's not at all possible for
OpenStreetMap users to resolve these conflicts in our database alone.

What needs to happen is bringing this information back to the local
government and asking them to correct the data and provide an
authoritative, public-domain source for everyone to use.

It's no good if OpenStreetMap has a more "accurate" boundary line which
follows a physical feature like a ridgeline, if the legal definition is
different. Determining this might require lawyers getting involved.

Now certainly OpenStreetMap data, which can include features like
ridgelines, waterways, roads and paths, which are often used to determine
historic land ownership boundaries, can be useful in determining if
existing databases are accurate and precise. But unless those outside
databases are corrected, our data will be inaccurate as well, when it comes
to legal issues like boundaries.

- Joseph Eisenberg

On Wed, Sep 2, 2020 at 11:39 AM Bradley White 
wrote:

> I echo this sentiment exactly as having taken place in California and in
>> my experiences with OSM.  This is most certainly a longer-term endeavor
>> (over several, even many years), but improvements in alignments between
>> data components which have been entered into OSM from my County GIS,
>> GreenInfo.org's publishing its "CPAD" (California Protected Area Database,
>> published semi-annually, see our wiki) and other sources HAVE INDEED
>> resulted in data improvements:  OSM influences CPAD, resulting in data
>> improvements, CPAD influenced County GIS data, resulting in data
>> improvements, later versions of these (County GIS and CPAD) data influenced
>> OSM all over again, resulting in data improvements...and upward, upward and
>> upward the spiral of more accurate, better-aligning data goes:  both
>> private and public.  OSM gets the results, so do others.  Win-win.  Taking
>> OSM out of the equation by asserting "these data don't belong in OSM" stops
>> this improvement pipeline (wholly unintentional on my part, but certainly
>> noticed) in its tracks.  (Yes, some data belong in OSM, some don't).
>
>
> I'm in strong agreement here. OSM provides a unique platform to synthesize
> multiple data sources in combination with field observation to produce
> something potentially better than any of these single sources are on their
> own. Trying to produce an accurate and detailed map of the entire US
> strictly off of field observation and satellite imagery is simply
> infesible, especially in remote, unpopulated areas. Many government and
> agency data sources are in conflict with each other over the same
> information; OSM can serve to provide "resolved" versions that are
> confirmed with ground observation where required.
>
> I agree that we shouldn't be importing parcel data wholesale, as-is. But,
> if real-life accuracy is important, the fact that much of the information
> we are trying to add in OSM (protected areas, land use, access
> restrictions) is differentiated along parcel boundaries is simply
> unavoidable to me. If this information is in the public domain and
> generally corroborates what is on the ground, so long as the data is worked
> through manually to confirm accuracy, I don't see the problem with using
> parcel information as a piece of the "puzzle" in producing an accurate and
> informative map.
> ___
> Talk-us mailing list
> Talk-us@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk-us
>
___
Talk-us mailing list
Talk-us@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk-us

Re: [Talk-us] Unintentional improvements in OSM data influencing / improving other databases

[Bradley White]

>
> I echo this sentiment exactly as having taken place in California and in
> my experiences with OSM.  This is most certainly a longer-term endeavor
> (over several, even many years), but improvements in alignments between
> data components which have been entered into OSM from my County GIS,
> GreenInfo.org's publishing its "CPAD" (California Protected Area Database,
> published semi-annually, see our wiki) and other sources HAVE INDEED
> resulted in data improvements:  OSM influences CPAD, resulting in data
> improvements, CPAD influenced County GIS data, resulting in data
> improvements, later versions of these (County GIS and CPAD) data influenced
> OSM all over again, resulting in data improvements...and upward, upward and
> upward the spiral of more accurate, better-aligning data goes:  both
> private and public.  OSM gets the results, so do others.  Win-win.  Taking
> OSM out of the equation by asserting "these data don't belong in OSM" stops
> this improvement pipeline (wholly unintentional on my part, but certainly
> noticed) in its tracks.  (Yes, some data belong in OSM, some don't).


I'm in strong agreement here. OSM provides a unique platform to synthesize
multiple data sources in combination with field observation to produce
something potentially better than any of these single sources are on their
own. Trying to produce an accurate and detailed map of the entire US
strictly off of field observation and satellite imagery is simply
infesible, especially in remote, unpopulated areas. Many government and
agency data sources are in conflict with each other over the same
information; OSM can serve to provide "resolved" versions that are
confirmed with ground observation where required.

I agree that we shouldn't be importing parcel data wholesale, as-is. But,
if real-life accuracy is important, the fact that much of the information
we are trying to add in OSM (protected areas, land use, access
restrictions) is differentiated along parcel boundaries is simply
unavoidable to me. If this information is in the public domain and
generally corroborates what is on the ground, so long as the data is worked
through manually to confirm accuracy, I don't see the problem with using
parcel information as a piece of the "puzzle" in producing an accurate and
informative map.
___
Talk-us mailing list
Talk-us@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk-us

[Talk-us] Unintentional improvements in OSM data influencing / improving other databases

[stevea]

On September 1, 2020 at 8:07:46 AM PDT, Kevin Kenny  
wrote:
> 
> In many of these cases OSM has an opportunity to improve the government data. 
>  A mapper can analyze the conflict, sort out the different data sources, 
> perhaps visit the site in the field, and produce a result that is more 
> accurate than any of the government data sets. It's been pretty quiet, but I 
> know that there some corrections from OSM have flowed back into some of the 
> government data sets that I use.

Starting a new thread.

I echo this sentiment exactly as having taken place in California and in my 
experiences with OSM.  This is most certainly a longer-term endeavor (over 
several, even many years), but improvements in alignments between data 
components which have been entered into OSM from my County GIS, GreenInfo.org's 
publishing its "CPAD" (California Protected Area Database, published 
semi-annually, see our wiki) and other sources HAVE INDEED resulted in data 
improvements:  OSM influences CPAD, resulting in data improvements, CPAD 
influenced County GIS data, resulting in data improvements, later versions of 
these (County GIS and CPAD) data influenced OSM all over again, resulting in 
data improvements...and upward, upward and upward the spiral of more accurate, 
better-aligning data goes:  both private and public.  OSM gets the results, so 
do others.  Win-win.  Taking OSM out of the equation by asserting "these data 
don't belong in OSM" stops this improvement pipeline (wholly unintentional on 
my part, but certainly noticed) in its tracks.  (Yes, some data belong in OSM, 
some don't).

This is a seldom-talked about real benefit OSM offers to both non-profit based 
data aggregators (like GreenInfo and their CPAD) and public ones (like County 
GIS departments).  Yes, a relatively high-degree of accuracy and careful 
mapping, skilled volunteers in OSM (who likely don't have the credentials of 
professional surveyors, but who are aware of basics like monument markers, 
"metes and bounds" in deeds and the like) ARE required.  So, even volunteer 
"citizen mappers" can go a long distance at improving data, simply by doing 
solid mapping in OSM.  And by remaining a database of high quality and careful 
curation, OSM earns the respect of other GIS professionals (public and private) 
who (over the longer-term) find the puzzle-pieces fitting together better.  The 
examples are numerous, thank you Kevin for providing several.

OSM will likely never become "authoritative" in the sense a cadastral database 
does for tax or land survey purposes, but as we keep our quality high, keep our 
mapping careful and pay attention to things like survey markers (we do), other 
mapping professionals will continue to look to us as "worthy enough" to include 
as a layer on their systems, for example.  OSM does not have the goal of being 
so "authoritative," nor should it in my opinion, but speaking personally, I do 
strive to map as accurately as I possibly can.  Our data being widely and 
deeply respected is a great result OSM can be proud to continue.

I can't count the number of times I've (more recently) heard from Land Trust 
mapping professionals, local public GIS professionals, non-profit GIS 
professionals and more "OSM is a fantastic and amazing resource, there is 
nothing else like it and the world of mapping is a far richer place because it 
exists."  (Or something very much like that).

Bottom line:  please don't scoff at the possibility that your careful and 
accurate mapping might influence "official" or "authoritative" GIS data.  It 
can, it has, it does and it will continue to do so.

SteveA
___
Talk-us mailing list
Talk-us@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk-us