Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Am Fr., 14. Feb. 2020 um 11:18 Uhr schrieb Colin Smale < colin.sm...@xs4all.nl>: > Yes I realise that but attention must be paid to all possible sources of > precision leakage. > > What use would proprietary parameters be? If they were used, are relevant > and kept private, this would impede the consumption of the data by any > clients. All GIS files must include, by value or by reference, the relevant > CRS, otherwise the contents can not be interpreted properly, can they? Or > are you thinking of the situation in China where they have a > state-controlled/licenced transformation? > > First, proprietary parameters does not mean you cannot have access to them, but you might have to pay for it. Secondly, you do not need the parameters for use of the data in a certain CRS but you need them for high precision conversions into another CRS. Cheers Martin ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 2020-02-14 10:18, Martin Koppenhoefer wrote:
> Am Do., 13. Feb. 2020 um 08:41 Uhr schrieb Colin Smale
> :
> Locations are stored in OSM as pairs of {lat,lon} and I assume these are both
> 64-bit floats in the database.
>
> AFAIK they are stored as integers (shifting the decimals)
>
> If so then then my comments about preserving precision still apply to all
> "client" software and I bet the majority uses float. Then an innocent update
> to a tag on a node can end up unintentionally moving the location slightly,
> losing precision.
My comment about precision lost through conversion was not about missing
floating point digits, but about conversions from one CRS to another,
where you may need additional (proprietary) grid parameters to do a high
precision conversion.
Yes I realise that but attention must be paid to all possible sources of
precision leakage.
What use would proprietary parameters be? If they were used, are
relevant and kept private, this would impede the consumption of the data
by any clients. All GIS files must include, by value or by reference,
the relevant CRS, otherwise the contents can not be interpreted
properly, can they? Or are you thinking of the situation in China where
they have a state-controlled/licenced transformation?___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Am Do., 13. Feb. 2020 um 08:41 Uhr schrieb Colin Smale <
colin.sm...@xs4all.nl>:
> Locations are stored in OSM as pairs of {lat,lon} and I assume these are
> both 64-bit floats in the database.
>
>
> AFAIK they are stored as integers (shifting the decimals)
>
> If so then then my comments about preserving precision still apply to all
> "client" software and I bet the majority uses float. Then an innocent
> update to a tag on a node can end up unintentionally moving the location
> slightly, losing precision.
>
>
My comment about precision lost through conversion was not about missing
floating point digits, but about conversions from one CRS to another, where
you may need additional (proprietary) grid parameters to do a high
precision conversion.
Cheers
Martin
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 13.02.20 08:41, Colin Smale wrote:
>>> Locations are stored in OSM as pairs of {lat,lon} and I assume these
>>> are both 64-bit floats in the database.
>>
>> AFAIK they are stored as integers (shifting the decimals)
>>
> If so then then my comments about preserving precision still apply to
> all "client" software and I bet the majority uses float. Then an
> innocent update to a tag on a node can end up unintentionally moving the
> location slightly, losing precision.
Floats are not necessarily more precise than fixed comma "integers",
as you don't need to waste bits on the exponent when you know it
is constant.
But even when taking a 32 bit longitude value, not 64 bit, with the
first 10 bits being the "integer" part, and the remaining 22 the
"fraction" part, we'd already be at 3cm or better.
Looking at the PBF file format description we actually have
// Granularity, units of nanodegrees, used to store coordinates in
this block
optional int32 granularity = 17 [default=100];
// Offset value between the output coordinates coordinates and the
granularity grid, in units of nanodegrees.
optional int64 lat_offset = 19 [default=0];
optional int64 lon_offset = 20 [default=0];
So we are at 64bit precision in nanodegrees, which brings us into
the range of possibly being as precise as low as a few percent
of a micrometer ...
That should be good enough for a while ...
--
hartmut
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 2020-02-13 00:15, Martin Koppenhoefer wrote:
> sent from a phone
>
>> Il giorno 13 feb 2020, alle ore 00:05, Colin Smale
>> ha scritto:
>>
>> Locations are stored in OSM as pairs of {lat,lon} and I assume these are
>> both 64-bit floats in the database.
>
> AFAIK they are stored as integers (shifting the decimals)
If so then then my comments about preserving precision still apply to
all "client" software and I bet the majority uses float. Then an
innocent update to a tag on a node can end up unintentionally moving the
location slightly, losing precision.___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
sent from a phone
> Il giorno 13 feb 2020, alle ore 00:05, Colin Smale ha
> scritto:
>
> Locations are stored in OSM as pairs of {lat,lon} and I assume these are both
> 64-bit floats in the database.
AFAIK they are stored as integers (shifting the decimals)
Cheers Martin
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 2020-02-12 23:34, Martin Koppenhoefer wrote:
> sent from a phone
>
> Il giorno 12 feb 2020, alle ore 14:06, Colin Smale ha
> scritto:
>
> Exactly this. A hobbyist or volunteer CAN verify an admin boundary (where it
> is available as open data) - it is independently verifiable. It is
> objectively of better quality than an OTG observation with a phone.
>
> this will obviously depend on the individual case, but in some instances in
> Europe I have seen the published open data boundaries were simplified
> geometries. Just because the original datum was precisely acquired doesn't
> necessarily imply that the published open data (often derivative data) is
> super accurate as well (our own errors in the transformation of the data
> during the import aside).
Good point about the simplification. If they do that by Douglas Peuker
then no points will be moved, but some points can be deleted. So any
points that make it through to the simplified data are accurate and
actually appear in the input. If the boundary, road or whatever is
actually curved, then we can subjectively improve on the published data
by inserting additional points, but we should use the accurate points as
a frame of reference and *leave them alone*. They are most likely to be
the very best data we can get our hands on, even if they are not 100%.
Concerning data quality and its definition:
Locations are stored in OSM as pairs of {lat,lon} and I assume these are
both 64-bit floats in the database. Any processing that we do on any
location should be done so as to minimise the error, so the
transformation parameters should be as accurate as possible and all
operations should be done at maximum precision - 64-bit floats ("double
precision" for the old guard) or, even better, 128-bit. When processing
this kind of data you need to be aware of these things, and principles
like these should also be considered "best practices". Results from
higher-precision inputs using higher-precision operations can be
considered to be *of a higher quality* than when a lower precision is
used. And when we "export" the data by translating the binary
representation to text (including XML), that should also be at a
sufficiently high precision, such that re-importing the data would lead
to the same binary representation. Every time data is loaded into an
editor, it is translated to a string, and when it is stored, it
translated back. This process must not lead to a loss of data precision!___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
sent from a phone > Il giorno 12 feb 2020, alle ore 14:06, Colin Smale ha > scritto: > > Exactly this. A hobbyist or volunteer CAN verify an admin boundary (where it > is available as open data) - it is independently verifiable. It is > objectively of better quality than an OTG observation with a phone. this will obviously depend on the individual case, but in some instances in Europe I have seen the published open data boundaries were simplified geometries. Just because the original datum was precisely acquired doesn’t necessarily imply that the published open data (often derivative data) is super accurate as well (our own errors in the transformation of the data during the import aside). Cheers Martin ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 2020-02-12 10:42, Frederik Ramm wrote:
> Hi,
>
> On 2020-02-12 10:28, Colin Smale wrote:
>
>> Where a boundary coincides with the centre line of
>> a road for example, and there is a discrepancy in OSM between the
>> locations of the two, there should be a recognition that the
>> professionally surveyed locations are more likely to be correct
>
> I disagree.
>
> What you are requesting here is that we blindly defer to authorities. "I
> cannot verify this - but a professional surveyor with his $10k equipment
> claims it is so - hence I guess I have to believe it."
Indeed, that is exactly what I am suggesting (without the "blindly"
bit). You can verify it, just not there and then with your cheap GPS.
OSM is built on trust, not mistrust.
> I think this is not how OpenStreetMap should be operating. I can see how
> to a professional surveyor the idea must be painful that someone comes
> along with their rubbish equipment and makes a change, but we *are* a
> project of hobbyists and volunteers, and something that a hobbyist and
> volunteer cannot verify ("don't touch this unless you invest $10k in
> equipment first!!!") should not be in OSM, and we should not worship
> precision that we cannot create ourselves.
Exactly this. A hobbyist or volunteer CAN verify an admin boundary
(where it is available as open data) - it is independently verifiable.
It is objectively of better quality than an OTG observation with a
phone.
The professional surveyor probably couldn't care less. I am thinking of
our downstream consumers. Sounds a bit like Brexit...
But some awareness amongst these hobbyists that some sources are better
than others, and their own measurements, even if they are more recent
than the contents of OSM, are not necessarily better, would surely not
be a bad thing.___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Colin doesn’t seem to be advocating for deference to and worship of authorities
in all situations. That’s an over the top interpretation.
It’s maybe better to say that it’s something to consider when evaluating data —
as we always look at a mappers context in OSM when looking at edits and
revisions.
Side point
> we *are* a project of hobbyists and volunteers
and professionals. And students and researchers. And anyone else who wants to
participate in an open map. Been that way since the beginning.
Let’s not cut ourselves short in comparison to “professional” tools. Many of
the software tools we’ve developed as a community are leading the industry.
Mikel
On Wednesday, February 12, 2020, 4:42 AM, Frederik Ramm
wrote:
Hi,
On 2020-02-12 10:28, Colin Smale wrote:
> Where a boundary coincides with the centre line of
> a road for example, and there is a discrepancy in OSM between the
> locations of the two, there should be a recognition that the
> professionally surveyed locations are more likely to be correct
I disagree.
What you are requesting here is that we blindly defer to authorities. "I
cannot verify this - but a professional surveyor with his $10k equipment
claims it is so - hence I guess I have to believe it."
I think this is not how OpenStreetMap should be operating. I can see how
to a professional surveyor the idea must be painful that someone comes
along with their rubbish equipment and makes a change, but we *are* a
project of hobbyists and volunteers, and something that a hobbyist and
volunteer cannot verify ("don't touch this unless you invest $10k in
equipment first!!!") should not be in OSM, and we should not worship
precision that we cannot create ourselves.
Bye
Frederik
--
Frederik Ramm ## eMail frede...@remote.org ## N49°00'09" E008°23'33"
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On Feb 12, 2020, at 12:28 AM, Martin Koppenhoefer
wrote:
> Start with "If A, then B" where A is "it is on the ground" and B is "you may
> map it." Now, try the contrapositive "If not B, then not A" (in logic
> notation: ¬B -> ¬A).
>
> this is not how complex situations work. "If its black it is not colored"
> does not mean that if its not colored it must be black (could be white, gray,
> etc.).
You make my point for me, Martin, and Colin reiterates it Our OTG "rule" fails
a simple logic test which should always be true ("proof by contrapositive") but
we in OSM (this mail-list, other places) say "A -> B is true, but ¬B -> ¬A (its
contrapositive) is not true!" That's broken logic about OTG, stripped to its
minimum.
It is exactly because OTG is a complex situation (breaking logic) that we must
improve OTG. If we can't state a logical rule which logically works, let's at
least start with a rule that has some exceptions we all agree upon: we map
what's OTG, but not some boundaries, mountain ranges, oceans... even though
they are neither OTG nor signed. We can improve OTG from there. Because that
is what OSM actually does.
Not to combine TOO much into one post: Frederik makes a good point that we
shouldn't blindly defer to authorities, however, when "an authoritative source"
is the ONLY thing which can provide a name (for example) in the absence of a
sign or other OTG evidence, how ELSE are we supposed to know what to tag
something? Please don't answer "ask locals" or "everybody just knows that" as
neither is a very good component of a "rule," as OTG claims to be (but isn't).
SteveA
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Hi,
On 2020-02-12 10:28, Colin Smale wrote:
> Where a boundary coincides with the centre line of
> a road for example, and there is a discrepancy in OSM between the
> locations of the two, there should be a recognition that the
> professionally surveyed locations are more likely to be correct
I disagree.
What you are requesting here is that we blindly defer to authorities. "I
cannot verify this - but a professional surveyor with his $10k equipment
claims it is so - hence I guess I have to believe it."
I think this is not how OpenStreetMap should be operating. I can see how
to a professional surveyor the idea must be painful that someone comes
along with their rubbish equipment and makes a change, but we *are* a
project of hobbyists and volunteers, and something that a hobbyist and
volunteer cannot verify ("don't touch this unless you invest $10k in
equipment first!!!") should not be in OSM, and we should not worship
precision that we cannot create ourselves.
Bye
Frederik
--
Frederik Ramm ## eMail frede...@remote.org ## N49°00'09" E008°23'33"
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 2020-02-12 09:28, Martin Koppenhoefer wrote: > I believe it is a misconception to think it must be "visible" on the ground, > rather it must be determinable on the ground / "in loco". There might well be > nothing to "see", but you could still check on the ground, by talking to the > local people, how to map something (particularly, how to call it). > >> Start with "If A, then B" where A is "it is on the ground" and B is "you may >> map it." Now, try the contrapositive "If not B, then not A" (in logic >> notation: ¬B -> ¬A). > > this is not how complex situations work. "If its black it is not colored" > does not mean that if its not colored it must be black (could be white, gray, > etc.). And this is why we should not try to map a continuum of possibilities onto a binary model. The OTG rule/guideline needs to accommodate these shades of grey. A rule that leads to so much discussion and so many exceptions is clearly not a good rule in its current form. Lets do some process improvement here! I want to come back to a point I made a few days ago as well, concerning location accuracy. If a point (possibly on an admin boundary) is imported into OSM from a source which has used cm-level surveying equipment, it is nothing short of WRONG if Joe Bloggs comes along with his $100 smartphone and moves that point based on a 3-satellite 2D GPS fix with a 100m GDOP. Where a boundary coincides with the centre line of a road for example, and there is a discrepancy in OSM between the locations of the two, there should be a recognition that the professionally surveyed locations are more likely to be correct - so in this example the highway should be moved to fit the boundary, and not the other way around! This professional data provides an extremely important collection of reference points, to which other data should be aligned - just like the trig points of older survey systems. OTG IS NOT ALWAYS BETTER! Elevations suffer from the same issues - except that the accuracy from GPS is even worse. Don't get me started on the differing definitions of "sea level" leading to meaningless elevations in OSM (because they don't specify to which datum they are relative).___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Am Mi., 12. Feb. 2020 um 01:29 Uhr schrieb stevea : > On Feb 11, 2020, at 3:45 PM, Mateusz Konieczny via talk < > talk@openstreetmap.org> wrote: > > OTG is not "everything must be mapped on survey", it means > > that direct survey (what is actually existing) overrides official data, > opinions and desires. > > I thank Mateusz for making (reiterating?) this important point. +1 > I believe some of us think OTG is an absolute rule which states "map what > is on the ground." Logically, we should be able to "derive" the > potentially equivalent statement "if you canNOT see it on-the-ground, you > may NOT (should not) map it." But that's not how we map, due to numerous > counter-examples (some boundaries, mountain ranges, oceans...). I believe it is a misconception to think it must be "visible" on the ground, rather it must be determinable on the ground / "in loco". There might well be nothing to "see", but you could still check on the ground, by talking to the local people, how to map something (particularly, how to call it). > Start with "If A, then B" where A is "it is on the ground" and B is "you > may map it." Now, try the contrapositive "If not B, then not A" (in logic > notation: ¬B -> ¬A). this is not how complex situations work. "If its black it is not colored" does not mean that if its not colored it must be black (could be white, gray, etc.). Cheers Martin ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On Feb 11 18 h 49 min 26 s UTC−5, Mateusz Konieczny via talk wrote:
> ??? just do not create unreasonably large multipolygons (or split existing,
> possibly undo import if it makes area uneditable and do it right).
Your answer seems to be that it is possible to map appropriately with the
current rules. Or maybe not, but anyway, let simply ignore these areas, not
find appropriate solution to add these areas to OSM. For north of Canada
alone, the superficy is closed to the size of Europe.
Your answer about polygons is simply a spin rethoric form (une pirouette) to
ignore the problem. Should we rename this project OpenEurope ?
Pierre
Le mardi 11 février 2020 18 h 49 min 26 s UTC−5, Mateusz Konieczny via talk
a écrit :
Feb 12, 2020, 00:07 by talk@openstreetmap.org:
Feb 11, 15:59, stevea wrote :
> Rather than get snarled in counter-examples, let's discuss how OTG isn't and
> can't be strictly
> followed in many cases. It IS followed in the majority of cases, but in
> those corner cases where
> it isn't, because it can't be ("nothing" is OTG), must be realistically
> addressed, likely in our wiki
> where we state the "rule" today, though going forward much better state a
> "guideline". I think
> we can get there, but it remains under discussion / construction.
I agree with this and I adds some other aspects to take into account below. The
areas not yet mapped in OSM have characteristics quite different than the
industrialiased regions / countries. And we cannot realistically count on
mappers to walk or cycle through huge isolated areas. We cannot expect people
that figth to survive, that have no good internet connexion to map intensively
there neighboorhood. And more then mappers, we need to think where we need to
revise OSM.
Note that it is not violating OTG. OTG is not "everything must be mapped on
survey", it means
that direct survey (what is actually existing) overrides official data,
opinions and desires.
If we could keep the wood landcover outside of OSM, it would greatly simplify
mapping of such areas and dramatically reduce the Mulipolygons problems where
huge multipolygons are created with inner for lakes and all the problems
related to this.
??? just do not create unreasonably large multipolygons (or split existing,
possibly undo import
if it makes area uneditable and do it right).
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On Feb 11, 2020, at 3:45 PM, Mateusz Konieczny via talk wrote: > OTG is not "everything must be mapped on survey", it means > that direct survey (what is actually existing) overrides official data, > opinions and desires. I thank Mateusz for making (reiterating?) this important point. I believe some of us think OTG is an absolute rule which states "map what is on the ground." Logically, we should be able to "derive" the potentially equivalent statement "if you canNOT see it on-the-ground, you may NOT (should not) map it." But that's not how we map, due to numerous counter-examples (some boundaries, mountain ranges, oceans...). So, a crucial way we DO map is "if it IS on-the-ground, then THAT is what we map." The idea of "if OTG, map THAT" shouldn't be different, but is different from "if not OTG, you may NOT map this" (which isn't true, strictly speaking, due to counterexamples). I think in logical terms this might be called "a fallacy of the contrapositive." Logically, this is problematic. Start with "If A, then B" where A is "it is on the ground" and B is "you may map it." Now, try the contrapositive "If not B, then not A" (in logic notation: ¬B -> ¬A). Or, "You may not map it if it is not on the ground." Usually, "proof by contrapositive" works, as "a statement and its contrapositive are logically equivalent, in the sense that if the statement is true, then its contrapositive is true and vice versa." But in OSM, this does NOT work, because of the preponderance of examples where ¬B -> ¬A fails: in some cases we DO map it, even though it is not on the ground. And therein lies what we have to fix: proof by contrapositive fails, when it shouldn't (logically), because OSM has made and does make numerous exceptions. Let's clarify how, when and why we do this, at least as a "first cut" at how we address this contradiction. I hope that clarifies, it does help sharpen focus about OTG in my mind, simply by being stated clearly. Well, stated logically — and for some, I realize, that might NOT be clear! SteveA ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Feb 12, 2020, 00:07 by talk@openstreetmap.org:
> Feb 11, 15:59, stevea wrote :
>
> > Rather than get snarled in counter-examples, let's discuss how OTG isn't
> > and can't be strictly
> > followed in many cases. It IS followed in the majority of cases, but in
> > those corner cases where
> > it isn't, because it can't be ("nothing" is OTG), must be realistically
> > addressed, likely in our wiki
> > where we state the "rule" today, though going forward much better state a
> > "guideline". I think
> > we can get there, but it remains under discussion / construction.
>
> I agree with this and I adds some other aspects to take into account below.
> The areas not yet mapped in OSM have characteristics quite different than the
> industrialiased regions / countries. And we cannot realistically count on
> mappers to walk or cycle through huge isolated areas. We cannot expect people
> that figth to survive, that have no good internet connexion to map
> intensively there neighboorhood. And more then mappers, we need to think
> where we need to revise OSM.
>
Note that it is not violating OTG. OTG is not "everything must be mapped on
survey", it means
that direct survey (what is actually existing) overrides official data,
opinions and desires.
> If we could keep the wood landcover outside of OSM, it would greatly simplify
> mapping of such areas and dramatically reduce the Mulipolygons problems where
> huge multipolygons are created with inner for lakes and all the problems
> related to this.
>
??? just do not create unreasonably large multipolygons (or split existing,
possibly undo import
if it makes area uneditable and do it right).
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Feb 11, 15:59, stevea wrote :
> Rather than get snarled in counter-examples, let's discuss how OTG isn't and
> can't be strictly
> followed in many cases. It IS followed in the majority of cases, but in
> those corner cases where
> it isn't, because it can't be ("nothing" is OTG), must be realistically
> addressed, likely in our wiki
> where we state the "rule" today, though going forward much better state a
> "guideline". I think
> we can get there, but it remains under discussion / construction.
I agree with this and I adds some other aspects to take into account below. The
areas not yet mapped in OSM have characteristics quite different than the
industrialiased regions / countries. And we cannot realistically count on
mappers to walk or cycle through huge isolated areas. We cannot expect people
that figth to survive, that have no good internet connexion to map intensively
there neighboorhood. And more then mappers, we need to think where we need to
revise OSM.
In Africa, I have often used ne highres imagery to retrace official imported
border limits that had been traced prior to the availability of detailed aerial
imageries.
Also there are remote areas like lake North of Quebec, where we cannot
realistically go and walk to trace every lake contour or follow thousand of km
of Power lines (+ bears, mosquitos), and we need some assistance for example to
trace hundred of thousand lakes like this one (imagery, assisted mapping,
imports ??).https://www.openstreetmap.org/way/75891758#map=11/61.3877/-73.4622
Mappers dont add wood cuts for roads and map styles take care of this. Could we
have a similar rule applied for Power lines, rivers and lakes ? And any
possibility to approach the landcover differently ? Mappers, Schema or
Developpers problem ?
What can we do to approach more realistically the problems, to establish good
basis for more mapping to come ?
Yes, let's avoid the problem saying this is the bad Canada imports. Or maybe,
we should think to revise the OSM schema which is not well adapted for such
areas.
There exist distinct Landcover layers like on this Maptiler OSM Vectorial Map
with a distinct Landcover layer
https://openlayers.org/en/latest/examples/mapbox-style.html
If we could keep the wood landcover outside of OSM, it would greatly simplify
mapping of such areas and dramatically reduce the Mulipolygons problems where
huge multipolygons are created with inner for lakes and all the problems
related to this.
Yes the problems must be realistically adressed if we want to progress.
Pierre
Le mardi 11 février 2020 15 h 59 min 12 s UTC−5, stevea
a écrit :
On Feb 11, 2020, at 12:05 PM, Mark Wagner wrote:
> Have you actually been to the US-Canada border? For thousands and
> thousands of kilometers, it's really obvious:
> https://upload.wikimedia.org/wikipedia/commons/a/aa/US-Canada_border_at_Crawford_State_Park_20130629.jpg
>
> Even when it's not as obvious as in that photo, there are still
> frequent boundary cairns. And yes, they're mapped in OSM:
> https://www.openstreetmap.org/node/1997617997
I have been there, and in British Columbia, as is your example. There will
always be counter-examples to a claim of "boundaries are not always obvious or
indicated on-the-ground," (as you did, here, with a cutline in the real world
some of these being mapped in OSM). Same with mountain ranges, oceans / bodies
of water, etc. that have no signage or evidence of them (named as they are)
being OTG. Simply stated, there ARE (and always will be) things we map which
are not OTG, making OTG not a rule strictly followed.
However, we map these anyway, and by the thousand. My point is that OSM
shouldn't pretend that the OTG "rule" is absolute, as it isn't. While I think
all of us (even its original proponent in 2007, as Mikel stated earlier) agree
that OTG is "an excellent guideline to be followed where it can be," others
(Colin, Yuri) here have chimed in or infer that it can't realistically be
absolute (as it isn't, and it can't). Me, too. There seems to be consensus
that "Independent verifiability" is a crucial component of Good Practice in
those cases where OTG cannot STRICTLY be followed, as in cases of invisible
boundaries, oceans without signage, and mountain ranges where we are forced to
concede "well, everybody simply KNOWS that these are 'The Alps' or 'The Rocky
Mountains.'" The solution here is "this (and its correct name) can be
independently verified, that's "good enough for OSM" even without OTG evidence.
https://wiki.osm.org/wiki/Talk:Good_practice#Supplementing_and_clarifying_the_On_The_Ground_.22rule.22
has input from Yuri and jeisenberg and I discussing whether unsigned routes
qualify for this treatment (we can't see them OTG, but we map them anyway, as a
public agency asserts their existence, though it hasn't signed them well).
While routes like this are a relatively minor (lesser) concern about OTG,
broader disc
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On Feb 11, 2020, at 2:41 PM, Mikel Maron wrote: > https://lists.openstreetmap.org/pipermail/talk/2020-February/083993.html Thank you. That's recent, and reminds me that I agreed with you as I (and I suspect others) support a yet-to-be, well-designed tagging protocol which clearly denotes these distinctions (national sovereignty vs. de facto control). This dichotomy (as in Crimea) is one more area where OTG "fails" (mm, better stated: "needs clarification"). The others (mountain ranges, oceans...) I mention in my previous (and lengthy) missives remain. This not only makes more plain OTG's problems (at its edges, mostly) but brings the topic back to the (original thread's) issue of Crimea, which isn't an edge-case, but something which OSM continues to face. While solutions don't seem easy or quickly forthcoming, I am heartened by good discussion here and in the Good Practices Talk page I linked earlier. Yes, OTG has some work to do. Again, I think we can get there. SteveA ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
https://lists.openstreetmap.org/pipermail/talk/2020-February/083993.html * Mikel Maron * +14152835207 @mikel s:mikelmaron On Tuesday, February 11, 2020, 04:42:42 PM EST, stevea wrote: Thanks, Mikel, but may I please ask what you mean by "control boundaries?" SteveA > On Feb 11, 2020, at 1:36 PM, Mikel Maron wrote: > > btw, I think it's entirely compatible to follow On the Ground, with tagging > that recognizes the distinction between political boundaries and control > boundaries. > > * Mikel Maron * +14152835207 @mikel s:mikelmaron ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Thanks, Mikel, but may I please ask what you mean by "control boundaries?" SteveA > On Feb 11, 2020, at 1:36 PM, Mikel Maron wrote: > > btw, I think it's entirely compatible to follow On the Ground, with tagging > that recognizes the distinction between political boundaries and control > boundaries. > > * Mikel Maron * +14152835207 @mikel s:mikelmaron ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
btw, I think it's entirely compatible to follow On the Ground, with tagging
that recognizes the distinction between political boundaries and control
boundaries.
* Mikel Maron * +14152835207 @mikel s:mikelmaron
On Tuesday, February 11, 2020, 03:55:48 PM EST, stevea
wrote:
On Feb 11, 2020, at 12:05 PM, Mark Wagner wrote:
> Have you actually been to the US-Canada border? For thousands and
> thousands of kilometers, it's really obvious:
> https://upload.wikimedia.org/wikipedia/commons/a/aa/US-Canada_border_at_Crawford_State_Park_20130629.jpg
>
> Even when it's not as obvious as in that photo, there are still
> frequent boundary cairns. And yes, they're mapped in OSM:
> https://www.openstreetmap.org/node/1997617997
I have been there, and in British Columbia, as is your example. There will
always be counter-examples to a claim of "boundaries are not always obvious or
indicated on-the-ground," (as you did, here, with a cutline in the real world
some of these being mapped in OSM). Same with mountain ranges, oceans / bodies
of water, etc. that have no signage or evidence of them (named as they are)
being OTG. Simply stated, there ARE (and always will be) things we map which
are not OTG, making OTG not a rule strictly followed.
However, we map these anyway, and by the thousand. My point is that OSM
shouldn't pretend that the OTG "rule" is absolute, as it isn't. While I think
all of us (even its original proponent in 2007, as Mikel stated earlier) agree
that OTG is "an excellent guideline to be followed where it can be," others
(Colin, Yuri) here have chimed in or infer that it can't realistically be
absolute (as it isn't, and it can't). Me, too. There seems to be consensus
that "Independent verifiability" is a crucial component of Good Practice in
those cases where OTG cannot STRICTLY be followed, as in cases of invisible
boundaries, oceans without signage, and mountain ranges where we are forced to
concede "well, everybody simply KNOWS that these are 'The Alps' or 'The Rocky
Mountains.'" The solution here is "this (and its correct name) can be
independently verified, that's "good enough for OSM" even without OTG evidence.
https://wiki.osm.org/wiki/Talk:Good_practice#Supplementing_and_clarifying_the_On_The_Ground_.22rule.22
has input from Yuri and jeisenberg and I discussing whether unsigned routes
qualify for this treatment (we can't see them OTG, but we map them anyway, as a
public agency asserts their existence, though it hasn't signed them well).
While routes like this are a relatively minor (lesser) concern about OTG,
broader discussion continues here (in talk). (I'm OK with that). But lest my
suggestion that we modify/soften OTG from a "hard rule" (which it isn't and
cannot be) into a wishy-washy, too-ill-defined "guideline," please understand
I'm stating OTG isn't a rule. Rather, it is an excellent guideline to be
followed where it can be and is, but it is a fact that it cannot be and is not
always followed. The particulars of how we better apply OTG going forward
might be difficult to describe well and reach consensus upon, but we shouldn't
let that deter us, even with disagreement.
Rather than get snarled in counter-examples, let's discuss how OTG isn't and
can't be strictly followed in many cases. It IS followed in the majority of
cases, but in those corner cases where it isn't, because it can't be ("nothing"
is OTG), must be realistically addressed, likely in our wiki where we state the
"rule" today, though going forward much better state a "guideline". I think we
can get there, but it remains under discussion / construction.
SteveA
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On Feb 11, 2020, at 12:05 PM, Mark Wagner wrote:
> Have you actually been to the US-Canada border? For thousands and
> thousands of kilometers, it's really obvious:
> https://upload.wikimedia.org/wikipedia/commons/a/aa/US-Canada_border_at_Crawford_State_Park_20130629.jpg
>
> Even when it's not as obvious as in that photo, there are still
> frequent boundary cairns. And yes, they're mapped in OSM:
> https://www.openstreetmap.org/node/1997617997
I have been there, and in British Columbia, as is your example. There will
always be counter-examples to a claim of "boundaries are not always obvious or
indicated on-the-ground," (as you did, here, with a cutline in the real world
some of these being mapped in OSM). Same with mountain ranges, oceans / bodies
of water, etc. that have no signage or evidence of them (named as they are)
being OTG. Simply stated, there ARE (and always will be) things we map which
are not OTG, making OTG not a rule strictly followed.
However, we map these anyway, and by the thousand. My point is that OSM
shouldn't pretend that the OTG "rule" is absolute, as it isn't. While I think
all of us (even its original proponent in 2007, as Mikel stated earlier) agree
that OTG is "an excellent guideline to be followed where it can be," others
(Colin, Yuri) here have chimed in or infer that it can't realistically be
absolute (as it isn't, and it can't). Me, too. There seems to be consensus
that "Independent verifiability" is a crucial component of Good Practice in
those cases where OTG cannot STRICTLY be followed, as in cases of invisible
boundaries, oceans without signage, and mountain ranges where we are forced to
concede "well, everybody simply KNOWS that these are 'The Alps' or 'The Rocky
Mountains.'" The solution here is "this (and its correct name) can be
independently verified, that's "good enough for OSM" even without OTG evidence.
https://wiki.osm.org/wiki/Talk:Good_practice#Supplementing_and_clarifying_the_On_The_Ground_.22rule.22
has input from Yuri and jeisenberg and I discussing whether unsigned routes
qualify for this treatment (we can't see them OTG, but we map them anyway, as a
public agency asserts their existence, though it hasn't signed them well).
While routes like this are a relatively minor (lesser) concern about OTG,
broader discussion continues here (in talk). (I'm OK with that). But lest my
suggestion that we modify/soften OTG from a "hard rule" (which it isn't and
cannot be) into a wishy-washy, too-ill-defined "guideline," please understand
I'm stating OTG isn't a rule. Rather, it is an excellent guideline to be
followed where it can be and is, but it is a fact that it cannot be and is not
always followed. The particulars of how we better apply OTG going forward
might be difficult to describe well and reach consensus upon, but we shouldn't
let that deter us, even with disagreement.
Rather than get snarled in counter-examples, let's discuss how OTG isn't and
can't be strictly followed in many cases. It IS followed in the majority of
cases, but in those corner cases where it isn't, because it can't be ("nothing"
is OTG), must be realistically addressed, likely in our wiki where we state the
"rule" today, though going forward much better state a "guideline". I think we
can get there, but it remains under discussion / construction.
SteveA
___
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On Sat, 8 Feb 2020 09:03:45 -0800 stevea wrote: > On Feb 8, 2020, at 2:58 AM, Rory McCann wrote: > > On 07.02.20 20:12, stevea wrote: > >> A well-known example is (national, other) boundaries, which > >> frequently do not exist "on the ground," > > National borders don't exist on the ground? huh? Have you ever > > actually _crossed_ an international border? I assure you they exist > > on the ground. From large infrastructure, to changes in the paint > > colour on roads, one can nearly always *see* where a border is. > > I didn't say "always" (I said "frequently," though I was being > parochial / local to me). Between USA and Canada, for thousands (and > thousands) of kilometers, the national border is entirely invisible. > True, in places, it exists in an observable way (some stone markers, > border crossings with paint-on-asphalt, even a fence or wall here or > there), but I'd even say "mostly," the USA-Canada national border > simply "isn't there:" nothing on-the-ground, that is. Have you actually been to the US-Canada border? For thousands and thousands of kilometers, it's really obvious: https://upload.wikimedia.org/wikipedia/commons/a/aa/US-Canada_border_at_Crawford_State_Park_20130629.jpg Even when it's not as obvious as in that photo, there are still frequent boundary cairns. And yes, they're mapped in OSM: https://www.openstreetmap.org/node/1997617997 -- Mark ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 2020-02-09 04:26, Joseph Eisenberg wrote: >> Re: "on a government map, by legal / statutory decree, from data >> authoritatively published on a website" > > These examples are not "good practice" sources for openstreetmap. > While many mappers import data from such sources, there is no "value > added" in the case that mappers are unable to confirm if the > government or "authoritative" data is accurate or inaccurate. Since > the data in Openstreetmap can be changed at any time, and often by > mistakes caused by new mappers, the authoritative database or source > will always be better for database users to consult directly, unless > openstreetmap can improve the originally imported data by checking it > against reality. I beg to differ. Importing positions of accurately and authoritatively surveyed objects gives us calibration points for our more manual work. We are all warned about distortions and offsets in aerial imagery, and 99% of our on-the-ground mappers will be using consumer-grade GPS. If the location of an admin boundary has been surveyed to centimetre accuracy as lat X / lon Y, the presence of this in the OSM database, plus an indication of its authoritative source, gives an invaluable frame of reference. If Joe Bloggs comes along with his smartphone and locates it at X+dX,Y+dY he needs to understand that it is he who has the inferior data, and he should refrain from "improving" OSM by changing the location of the boundary. If other objects like rivers, highways etc should probably coincide with the admin boundary but don't, Joe Bloggs needs to consider that the professionally surveyed data is more likely to be correct before moving the admin boundary in OSM to fit his imperfect data. Besides, OSM strives not only to be "complete" but also "useful". If imports can increase the usefulness of OSM, it is likely to positively impact its adoption. So what's not to like? A subject often ignored in OSM is defining what me mean by "data quality." Quality is always relative to some definition of perfection. Is a point entered by an "OTG mapper" with a smartphone, of higher quality than a definitive, authoritative survey? > Remember, this is the "good practice" page we are talking about > editing, not the "how things really are done" page: we want to focuse > on the "Gold Standard", best practices. Irrespective of the discussion above, Best Practises and Gold Standards can often usefully be illustrated by negative examples. Standards have quality too! A good standard will be unambiguous; one that is vague and open to a lot of interpretation is not a good standard.___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
> Re: "Similarly, type=route relations (road, bicycle, hiking, equestrian...) > enter OSM from ODbL-compatible government-published maps, yet remain unsigned > (or poorly signed) in the real world." Please do not add this section. Most types of route relation should only be mapped if they are actually signed. Some which are fixed-route public services can be mapped based on actually riding the route, which is also a real-world method of verification which does not depend on consulting an external map or document. I do not think the "good practice" page should mention mapping routes which are not verifiable in the real world, which only exist on paper. While some mappers like to add such things (like "proposed" bicycle routes or hiking routes which only exist in guidebooks and have no signs), this is not a good practice. > Re: "on a government map, by legal / statutory decree, from data > authoritatively published on a website" These examples are not "good practice" sources for openstreetmap. While many mappers import data from such sources, there is no "value added" in the case that mappers are unable to confirm if the government or "authoritative" data is accurate or inaccurate. Since the data in Openstreetmap can be changed at any time, and often by mistakes caused by new mappers, the authoritative database or source will always be better for database users to consult directly, unless openstreetmap can improve the originally imported data by checking it against reality. Remember, this is the "good practice" page we are talking about editing, not the "how things really are done" page: we want to focuse on the "Gold Standard", best practices. - Joseph Eisenberg On 2/9/20, stevea wrote: > Done: > > https://wiki.osm.org/wiki/Talk:Good_practice#Supplementing_and_clarifying_the_On_The_Ground_.22rule.22 > > Follow it there, if you like. > > SteveA > >> On Feb 8, 2020, at 12:04 PM, Yuri Astrakhan >> wrote: >> >> I am in favor of this or similar language. I think for a more vote-like >> discussion it might be better to use the wiki talk page (easier to add +1s >> and short comments). > > ___ > talk mailing list > talk@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk > ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Done: https://wiki.osm.org/wiki/Talk:Good_practice#Supplementing_and_clarifying_the_On_The_Ground_.22rule.22 Follow it there, if you like. SteveA > On Feb 8, 2020, at 12:04 PM, Yuri Astrakhan wrote: > > I am in favor of this or similar language. I think for a more vote-like > discussion it might be better to use the wiki talk page (easier to add +1s > and short comments). ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
I am in favor of this or similar language. I think for a more vote-like discussion it might be better to use the wiki talk page (easier to add +1s and short comments). On Sat, Feb 8, 2020 at 2:59 PM stevea wrote: > I don't know if here or https://wiki.osm.org/wiki/Talk:Good_practice is a > better place to discuss and eventually insert these suggested improvements > into https://wiki.osm.org/wiki/Good_practice#Verifiability (and its first > section, "Map what's on the ground"). > > I suggest adding these essences of this thread there: > > "'Independent verifiability' is a crucial component of the Good Practice > of mapping what is on the ground, as sometimes there IS no evidence > on-the-ground that a map feature should be appropriately tagged anything in > particular. For example, some boundaries are effectively invisible, but > OSM maps them (and should). Also, there are no or few signs which say > "Pacific Ocean" or "Rocky Mountains," yet OSM authoritatively maps these > natural=* features with an agreed-correct name=* tag. Similarly, there are > routes (road, bicycle, hiking, equestrian...) which might exist on a > government-published map (and hence are ODbL-compatible) yet remain > unsigned (or poorly signed) in the real world. From what authority must we > determine the source "verifiability" of these "invisible" or "unsigned" map > features? As long as these are "independently verifiable" (by a government > map, legal / statutory decree, data authoritatively published on a website, > by unanimous agreement among locals and a wider public or at least with > very wide consensus), the map feature with its verifiable tags may be > entered into OSM following Good Practice. 'Independent verifiability' > means any member of the public, freely, anytime and with no special > privileges can 'consult the source' and verify the data." > > I'm simply tossing that out here, if it shouldn't stick, please fix it. I > think it important that the phrasing is first vetted (here or on the Talk > page) and I do think something like this should be entered into our > Good_practice wiki to clarify OTG as we have discussed it here. > > Thanks in advance for any brief review and comments / suggestions you > might offer, > SteveA > ___ > talk mailing list > talk@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk > ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
I don't know if here or https://wiki.osm.org/wiki/Talk:Good_practice is a better place to discuss and eventually insert these suggested improvements into https://wiki.osm.org/wiki/Good_practice#Verifiability (and its first section, "Map what's on the ground"). I suggest adding these essences of this thread there: "'Independent verifiability' is a crucial component of the Good Practice of mapping what is on the ground, as sometimes there IS no evidence on-the-ground that a map feature should be appropriately tagged anything in particular. For example, some boundaries are effectively invisible, but OSM maps them (and should). Also, there are no or few signs which say "Pacific Ocean" or "Rocky Mountains," yet OSM authoritatively maps these natural=* features with an agreed-correct name=* tag. Similarly, there are routes (road, bicycle, hiking, equestrian...) which might exist on a government-published map (and hence are ODbL-compatible) yet remain unsigned (or poorly signed) in the real world. From what authority must we determine the source "verifiability" of these "invisible" or "unsigned" map features? As long as these are "independently verifiable" (by a government map, legal / statutory decree, data authoritatively published on a website, by unanimous agreement among locals and a wider public or at least with very wide consensus), the map feature with its verifiable tags may be entered into OSM following Good Practice. 'Independent verifiability' means any member of the public, freely, anytime and with no special privileges can 'consult the source' and verify the data." I'm simply tossing that out here, if it shouldn't stick, please fix it. I think it important that the phrasing is first vetted (here or on the Talk page) and I do think something like this should be entered into our Good_practice wiki to clarify OTG as we have discussed it here. Thanks in advance for any brief review and comments / suggestions you might offer, SteveA ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
Very well stated, Colin. I agree that "independent verifiability" is at the heart of OTG and what we mean to distill from it as crucially important and a tenet of OSM that we can all agree upon (well, I hope so, anyway). By explicitly stating that John Random Public can "consult the source" (freely, in all senses) to determine "what is" even (or especially) if something is NOT on-the-ground, we actually DO largely encompass many of the exceptions of "but I can't SEE it on the ground." We may have more work to do to be more explicit, but this goes a long way: thank you! SteveA > On Feb 8, 2020, at 9:42 AM, Colin Smale wrote: > > On 2020-02-08 18:03, stevea wrote: > >> See, "the on the ground rule," to the best of my ability to determine it (an >> exception is your opinion as you explicitly express here, and that's part of >> the problem with it), isn't clearly defined and it needs the elasticity of >> such ad hoc exceptions. It doesn't say (explicitly, anywhere, except in >> your exception) "we ask people there and look at books, other maps, >> Wikipedia, travel books, organizations...if the name is used in reality." >> You do (here, as an "exception," by way of clarifying your understanding of >> OTG) but if all of that is true, OSM should say so: formally and as fully >> as possible. >> > The most important aspect of the "on the ground" rule is that things are > independently verifiable, i.e. given the evidence, anybody would come to the > same conclusion. Physical evidence is obviously very useful - for example, > either a highway is present, or it is not. But other sources, provided they > are freely accessible, can also provide facts that are sufficiently > verifiable. In the case of the US-CA border, I guess the treaty or whatever > is publicly accessible, so there can be no arguments about where the border > is in a legal sense. Of course not all boundaries are fully specified in > treaties, but I suspect this one is. > > So I suggest the "On The Ground" rule should be replaced by a requirement for > independent verifiability; our traditional definition of OTG is sufficient > but not necessary for compliance. > > Independent viability means (to me) a random member of the public, with no > special privileges, and without payment, and at any time, should be able to > "consult the source". > > ___ > talk mailing list > talk@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 2020-02-08 18:03, stevea wrote: > See, "the on the ground rule," to the best of my ability to determine it (an > exception is your opinion as you explicitly express here, and that's part of > the problem with it), isn't clearly defined and it needs the elasticity of > such ad hoc exceptions. It doesn't say (explicitly, anywhere, except in your > exception) "we ask people there and look at books, other maps, Wikipedia, > travel books, organizations...if the name is used in reality." You do (here, > as an "exception," by way of clarifying your understanding of OTG) but if all > of that is true, OSM should say so: formally and as fully as possible. The most important aspect of the "on the ground" rule is that things are independently verifiable, i.e. given the evidence, anybody would come to the same conclusion. Physical evidence is obviously very useful - for example, either a highway is present, or it is not. But other sources, provided they are freely accessible, can also provide facts that are sufficiently verifiable. In the case of the US-CA border, I guess the treaty or whatever is publicly accessible, so there can be no arguments about where the border is in a legal sense. Of course not all boundaries are fully specified in treaties, but I suspect this one is. So I suggest the "On The Ground" rule should be replaced by a requirement for independent verifiability; our traditional definition of OTG is sufficient but not necessary for compliance. Independent viability means (to me) a random member of the public, with no special privileges, and without payment, and at any time, should be able to "consult the source".___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On Feb 8, 2020, at 2:58 AM, Rory McCann wrote: > On 07.02.20 20:12, stevea wrote: >> A well-known example is (national, other) boundaries, which >> frequently do not exist "on the ground," > National borders don't exist on the ground? huh? Have you ever actually > _crossed_ an international border? I assure you they exist on the > ground. From large infrastructure, to changes in the paint colour on > roads, one can nearly always *see* where a border is. I didn't say "always" (I said "frequently," though I was being parochial / local to me). Between USA and Canada, for thousands (and thousands) of kilometers, the national border is entirely invisible. True, in places, it exists in an observable way (some stone markers, border crossings with paint-on-asphalt, even a fence or wall here or there), but I'd even say "mostly," the USA-Canada national border simply "isn't there:" nothing on-the-ground, that is. We (OSM) cannot say that "nearly always" characterizes how one can *see* where a border is. And yes, I have crossed international borders, dozens, maybe hundreds of times. By contrast (thanks for the link and photo, Minh), our wiki https://wiki.osm.org/wiki/United_States/Boundaries#National_boundary shows the stark demarcation between San Diego (California, USA) and Tijuana (Baja California, México), Having frequently crossed it, I know this boundary well and it is an example of an OBSERVABLE boundary OTG. But again, not all are. Nor are MANY things in OSM "observable OTG" like this, yet they remain in the map (and more are added each day). OSM should explicitly acknowledge this. >> Other examples include large bodies of water and mountain ranges. >> I've lived on the Pacific coast most of my life and been to dozens of >> beaches, but never once on any beach have I seen a sign which reads >> "Pacific Ocean." Same with no signs at the edge of or in the middle >> of "Rocky Mountains" or "The Alps." (I've been, and I haven't seen). >> Yet, OSM maps oceans and mountain ranges. How do we know their names >> without anything on the ground? > We ask people there. We look at books, at maps, at whether there is a > detailed Wikipedia article on the topic, do are travel books published that > refer to this area as that, do organisations that cover that area use that > term. We look to see if the name is _used in reality_. > > That's the "on the ground rule". IMO "on the ground" refers to "observable > reality". See, "the on the ground rule," to the best of my ability to determine it (an exception is your opinion as you explicitly express here, and that's part of the problem with it), isn't clearly defined and it needs the elasticity of such ad hoc exceptions. It doesn't say (explicitly, anywhere, except in your exception) "we ask people there and look at books, other maps, Wikipedia, travel books, organizations...if the name is used in reality." You do (here, as an "exception," by way of clarifying your understanding of OTG) but if all of that is true, OSM should say so: formally and as fully as possible. Such fuzzy semantics land us where we are: in ambiguity. Let us acknowledge that such exceptions (and there are many of them) exist and best deserve to be explicitly described. We should do so for the betterment of the rule. And, "rule" becomes "good guideline, applicable where it can be easily and unambiguously applied, but with sensible exceptions we can largely but probably not exhaustively delineate." With such dialog, we get closer, yes. SteveA ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 08.02.20 11:58, Rory McCann wrote: On 07.02.20 20:12, stevea wrote: A well-known example is (national, other) boundaries, which frequently do not exist "on the ground," National borders don't exist on the ground? huh? Have you ever actually _crossed_ an international border? I assure you they exist on the ground. From large infrastructure, to changes in the paint colour on roads, one can nearly always *see* where a border is. might be easy to forget what borders can look like when being in a "Schengen" country, especially if it is completely surrounded by other Schengen states. E.g. I once drove from Belgium to France by accident, and as it was in a very rural area it took a while until I finally noticed I had missed some turn earlier on. But even then, on the major roads it is hard to miss that you just entered a different country. You can't deduct the exact border line by the centimeter by such observations, but you will usually be right within less than a kilometer if you interpolate from those clearly marked crossing points. Disputed areas are usually much wider than that, and I'm pretty sure you will notice when getting to what Russia thinks the current border line is, and try to cross? ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
[OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground
On 07.02.20 20:12, stevea wrote: A well-known example is (national, other) boundaries, which frequently do not exist "on the ground," National borders don't exist on the ground? huh? Have you ever actually _crossed_ an international border? I assure you they exist on the ground. From large infrastructure, to changes in the paint colour on roads, one can nearly always *see* where a border is. Other examples include large bodies of water and mountain ranges. I've lived on the Pacific coast most of my life and been to dozens of beaches, but never once on any beach have I seen a sign which reads "Pacific Ocean." Same with no signs at the edge of or in the middle of "Rocky Mountains" or "The Alps." (I've been, and I haven't seen). Yet, OSM maps oceans and mountain ranges. How do we know their names without anything on the ground? We ask people there. We look at books, at maps, at whether there is a detailed Wikipedia article on the topic, do are travel books published that refer to this area as that, do organisations that cover that area use that term. We look to see if the name is _used in reality_. That's the "on the ground rule". IMO "on the ground" refers to "observable reality". ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
