I often add tracks from satellite imagery, and also do occasionally add missing tracktype tagging from that imagery.
The tricky bit is to understand that there are no physical barriers which are not visible on the imagery, but the tracktype, surface and smoothness are often easy to guess correctly, with the proviso that, when in doubt I put lower quality indication tags. I do that only in areas which I generally know, i.e. I have used many tracks in the area, and know from that how they typically look like. So, I use some kind of NA (Natural Intelligence) learning process to interpret the satellite images. >From my user experience (on bicycle) I find it important that a barrier-free track exists, that I can follow at my own risk as far as surface quality is concerned than not to have it on the map. Barriers (gates, fences, access forbidden signs) are the real risk in this. I often consult GPX tracks and also the Strava heat map to get an idea of which tracks are used. I would not, however, apply this approach to an area which I do not generally know. Doing this on a world-wide scale is most likely a bit more complex, but I could imagine that a person who is doing that continuously develops a capability to interpret well the satellite photos regarding tracktype. But, by my own experience, it is much more common to encounter access problems than to encounter tracktype-related problems. In summary I would not advocate a revert unless there are at least some real examples of errors. Volker (mapping often in the treeless and flat agricultural country side of the Po valley in Italy) On Sat, 18 Jul 2020 at 19:44, <talk-requ...@openstreetmap.org> wrote: > Send talk mailing list submissions to > talk@openstreetmap.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.openstreetmap.org/listinfo/talk > or, via email, send a message with subject or body 'help' to > talk-requ...@openstreetmap.org > > You can reach the person managing the list at > talk-ow...@openstreetmap.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of talk digest..." > > > Today's Topics: > > 1. Re: Planned revert of added surface and tracktype tags > without local knowledge in various countries (Andy Townsend) > 2. Re: Planned revert of added surface and tracktype tags > without local knowledge in various countries (Rory McCann) > 3. Re: Planned revert of added surface and tracktype tags > without local knowledge in various countries (stevea) > 4. Re: Planned revert of added surface and tracktype tags > without local knowledge in various countries (Florimond Berthoux) > 5. Re: Planned revert of added surface and tracktype tags > without local knowledge in various countries (Mateusz Konieczny) > 6. Re: Planned revert of added surface and tracktype tags > without local knowledge in various countries (stevea) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 18 Jul 2020 15:01:02 +0100 > From: Andy Townsend <ajt1...@gmail.com> > To: talk@openstreetmap.org > Subject: Re: [OSM-talk] Planned revert of added surface and tracktype > tags without local knowledge in various countries > Message-ID: <43bdf582-5768-bf99-ed8e-d802f5086...@gmail.com> > Content-Type: text/plain; charset=utf-8; format=flowed > > On 18/07/2020 11:53, Michael Reichert wrote: > > I do not believe that one can add reliable tracktype=* information from > > satellite imagery without having some ground truth knowledge in order to > > know how to interpret the imagery in that region. > > I think that "without having some ground truth knowledge" is the key > part there. I know from personal experience that if I was to try and > add tracktype or detailed surface information based purely on imagery > I'd get it wrong lots of the time. Very often when I'm updating OSM > I'll add the details that I recorded while I was there, and look at what > they say and what it looks like on the available imagery and the two can > be very different. > > Best Regards, > > Andy > > > > > > ------------------------------ > > Message: 2 > Date: Sat, 18 Jul 2020 16:09:29 +0200 > From: Rory McCann <r...@technomancy.org> > To: Andy Townsend <ajt1...@gmail.com>, talk@openstreetmap.org > Subject: Re: [OSM-talk] Planned revert of added surface and tracktype > tags without local knowledge in various countries > Message-ID: <10208f7e-2a01-5537-f6cf-69e104199...@technomancy.org> > Content-Type: text/plain; charset=utf-8; format=flowed > > In addition (I can't find the link now but) I recall reading about the > death of a hiker or climber who used some app which used OSM data, and > the app didn't distinguish between track_types (or there was no > track_type data for that route), so the hiker presumed it was OK to go > on, and subsequently died. > > On 18.07.20 16:01, Andy Townsend wrote: > > On 18/07/2020 11:53, Michael Reichert wrote: > >> I do not believe that one can add reliable tracktype=* information from > >> satellite imagery without having some ground truth knowledge in order to > >> know how to interpret the imagery in that region. > > > > I think that "without having some ground truth knowledge" is the key > > part there. I know from personal experience that if I was to try and > > add tracktype or detailed surface information based purely on imagery > > I'd get it wrong lots of the time. Very often when I'm updating OSM > > I'll add the details that I recorded while I was there, and look at what > > they say and what it looks like on the available imagery and the two can > > be very different. > > > > Best Regards, > > > > Andy > > > > > > > > _______________________________________________ > > talk mailing list > > talk@openstreetmap.org > > https://lists.openstreetmap.org/listinfo/talk > > > > ------------------------------ > > Message: 3 > Date: Sat, 18 Jul 2020 07:19:55 -0700 > From: stevea <stevea...@softworkers.com> > To: Rory McCann <r...@technomancy.org> > Cc: Andy Townsend <ajt1...@gmail.com>, talk@openstreetmap.org > Subject: Re: [OSM-talk] Planned revert of added surface and tracktype > tags without local knowledge in various countries > Message-ID: <50cf488c-de93-4b8d-b96e-2c096b545...@softworkers.com> > Content-Type: text/plain; charset=us-ascii > > On Jul 18, 2020, at 7:09 AM, Rory McCann <r...@technomancy.org> wrote: > > In addition (I can't find the link now but) I recall reading about the > death of a hiker or climber who used some app which used OSM data, and the > app didn't distinguish between track_types (or there was no track_type data > for that route), so the hiker presumed it was OK to go on, and subsequently > died. > > Let us be clear as crystal as we pause to realize the key part of this: > "so the hiker presumed it was OK." The hiker made that choice. Any > assumption that OSM has ANYthing to do with a subsequent death is specious > and only that: an assumption. > > No, maps don't "make people" do foolish things. Yes, people do foolish > things, by their own volition. Not because "the GPS made me do it" or "the > map is responsible" (somehow). OSM makes no warranties as to fitness or > merchantability for any particular purpose. Do I (we) really need to say > this? It's sad if we do. > > I recently had someone from my local Land Trust imply that because I > entered trails under development from their public map (and tagged > access=no) that somehow OSM was responsible for increased trespassing. > Ridiculous. Maps don't make people choose to break the law, people do. I > set him straight and we get along fine. > > SteveA > California > > > ------------------------------ > > Message: 4 > Date: Sat, 18 Jul 2020 18:51:57 +0200 > From: Florimond Berthoux <florimond.berth...@gmail.com> > To: "talk@openstreetmap.org" <talk@openstreetmap.org> > Subject: Re: [OSM-talk] Planned revert of added surface and tracktype > tags without local knowledge in various countries > Message-ID: > <CAELphJDMQw7KyqBKbDAR7o6hoj=N9= > hqev0jz-hawynnol7...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > I see no big issue of using only aerial images to set track_type or > surface. > You can get a fairly good result with such sources. > So no, you should not blindly revert its modifications. > If the estimation was really bad almost all the time why not, but here the > example given is ok. > > Le sam. 18 juil. 2020 à 12:56, Michael Reichert <osm...@michreichert.de> a > écrit : > > > Hi, > > > > while reviewing changes in my local area, I discovered that user Modest7 > > has been adding tracktype=* tags to lots of highway=track at various > > locations. I asked him what sources he used apart from the satellite > > imagery mentioned in the imagery_used=* tag of his changesets. See > > https://www.openstreetmap.org/changeset/87236896 for a discussion with > > him. > > > > I do not believe that one can add reliable tracktype=* information from > > satellite imagery without having some ground truth knowledge in order to > > know how to interpret the imagery in that region. Adding estimated > > tracktype=* does not help OSM on the long term. People how rely on the > > information (e.g. some wanting to drive or cycle on that track) are > > disappointed about this low-quality OSM data. Mappers who decide where > > to map assume these roads to be mapped properly. IMHO, adding > > fixme=resurvey tracktype will not improve it. Data consumers usually do > > not use tags like fixme=* In the case of imports (another type of mass > > editing), we say that an import must not add fixme=* to cover > > shortcomings of the data to be imported because they usually do not get > > fixed in a reasonable time. Therefore, I plan to revert these changes. > > > > Modest7 does not seem to realise that estimating tracktype from > > satellite imagery is not doing a service to OSM. I am currently > > preparing a revert of all additions of surface=* and tracktype=* by him > > he uploaded since 1 January 2020 [1]. The revert will only edit tags, > > geometry will stay unchanged. I revert changes on surface as well > > because that's not very different to tracktype except that it applies to > > other types of roads as well. > > > > The countries which will be affected are: > > Germany > > Denmark > > Turkey > > United States > > Poland > > Ukraine > > Morocco > > Czech Republic > > Lithuania > > Sweden > > Norway > > eSwatini > > > > A changeset discussion with him can be found at > > https://www.openstreetmap.org/changeset/87236896 > > > > Best regards > > > > Michael > > > > > > [1] This date is not fixed yet. > > > > _______________________________________________ > > talk mailing list > > talk@openstreetmap.org > > https://lists.openstreetmap.org/listinfo/talk > > > > > -- > Florimond Berthoux > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.openstreetmap.org/pipermail/talk/attachments/20200718/0c3fc3d0/attachment-0001.htm > > > > ------------------------------ > > Message: 5 > Date: Sat, 18 Jul 2020 19:29:50 +0200 (CEST) > From: Mateusz Konieczny <matkoni...@tutanota.com> > To: Michael Reichert <osm...@michreichert.de> > Cc: "talk@openstreetmap.org" <talk@openstreetmap.org> > Subject: Re: [OSM-talk] Planned revert of added surface and tracktype > tags without local knowledge in various countries > Message-ID: <mcxyo2t--...@tutanota.com> > Content-Type: text/plain; charset="utf-8" > > Can you link affected data in Poland? > > In Poland you actually can reliably estimate real tracktype based solely > on high quality aerial images (not satellite imagery that is unlikely to > be > sufficient), typically Geoportal 2 aerial and LIDAR data available in ISOK > Cień dataset. > > Note that your planned automatic revert likely counts as automatic > edits and needs to fullfill > https://wiki.openstreetmap.org/wiki/Automated_Edits_code_of_conduct > requirements, including support from other editors. > > Jul 18, 2020, 12:53 by osm...@michreichert.de: > > > Hi, > > > > while reviewing changes in my local area, I discovered that user Modest7 > > has been adding tracktype=* tags to lots of highway=track at various > > locations. I asked him what sources he used apart from the satellite > > imagery mentioned in the imagery_used=* tag of his changesets. See > > https://www.openstreetmap.org/changeset/87236896 for a discussion with > him. > > > > I do not believe that one can add reliable tracktype=* information from > > satellite imagery without having some ground truth knowledge in order to > > know how to interpret the imagery in that region. Adding estimated > > tracktype=* does not help OSM on the long term. People how rely on the > > information (e.g. some wanting to drive or cycle on that track) are > > disappointed about this low-quality OSM data. Mappers who decide where > > to map assume these roads to be mapped properly. IMHO, adding > > fixme=resurvey tracktype will not improve it. Data consumers usually do > > not use tags like fixme=* In the case of imports (another type of mass > > editing), we say that an import must not add fixme=* to cover > > shortcomings of the data to be imported because they usually do not get > > fixed in a reasonable time. Therefore, I plan to revert these changes. > > > > Modest7 does not seem to realise that estimating tracktype from > > satellite imagery is not doing a service to OSM. I am currently > > preparing a revert of all additions of surface=* and tracktype=* by him > > he uploaded since 1 January 2020 [1]. The revert will only edit tags, > > geometry will stay unchanged. I revert changes on surface as well > > because that's not very different to tracktype except that it applies to > > other types of roads as well. > > > > The countries which will be affected are: > > Germany > > Denmark > > Turkey > > United States > > Poland > > Ukraine > > Morocco > > Czech Republic > > Lithuania > > Sweden > > Norway > > eSwatini > > > > A changeset discussion with him can be found at > > https://www.openstreetmap.org/changeset/87236896 > > > > Best regards > > > > Michael > > > > > > [1] This date is not fixed yet. > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.openstreetmap.org/pipermail/talk/attachments/20200718/b756c387/attachment-0001.htm > > > > ------------------------------ > > Message: 6 > Date: Sat, 18 Jul 2020 10:42:41 -0700 > From: stevea <stevea...@softworkers.com> > To: Michael Reichert <osm...@michreichert.de> > Cc: Mateusz Konieczny <matkoni...@tutanota.com>, > "talk@openstreetmap.org" <talk@openstreetmap.org> > Subject: Re: [OSM-talk] Planned revert of added surface and tracktype > tags without local knowledge in various countries > Message-ID: <5ed5660c-e8fa-4a7e-8450-8e43cf1c8...@softworkers.com> > Content-Type: text/plain; charset=us-ascii > > I modestly (on occasion) set tracktype=* based on imagery, but only using > higher-quality imagery where I have high confidence I can quite accurately > do so. On those few occasions where I later visit the site / track and am > able to glean how accurate my tagging was, I've either never had to change > it to a different value or it was such a long time between setting and > visiting that it was one value different (higher based on increased use, > lower based on decreased use and falling into reverting to the landscape). > So, done with skill, this sort of armchair mapping can be and is done > accurately quite frequently, in my experience of both doing this and > observing others doing this (and reading the confirmation of that here and > now). > > That is me, your mileage may vary, though as others have said similar > (that they do this), I, too, would refrain from performing a revert. If, > on the other hand, you are certain that _individual_ tracks are clearly > wrong, I'd say go ahead and change those one-at-a-time, but a wholesale > revert, no, that seems like overkill. > > SteveA > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk > > > ------------------------------ > > End of talk Digest, Vol 191, Issue 13 > ************************************* >
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