>>Especially when the only imagery available is Landsat.... I remember the days when it was trudge out in the rain with the Garmin then upload the GPS traces only to find a straight road was no longer straight because of the wet leaves in the trees above.
Cheerio John On 30 June 2017 at 15:03, James <james2...@gmail.com> wrote: > Especially when the only imagery available is Landsat.... > > On Jun 30, 2017 2:18 PM, "Frank Steggink" <stegg...@steggink.org> wrote: > >> Hi Jochen, >> >> Maybe I'm not understanding it, but in the OSM inspector [1] I just see >> one case of old style multipolygon, in Manitoba. Last week, when you posted >> your original message, I just saw one case in New Brunswick. IIRC, it was a >> park, not even from the Canvec import. >> >> In the OSM inspector other errors can be seen, but the most prevalent one >> is "Touching rings". Maybe indeed a case of suboptimal mapping, but nothing >> which seems urgent to me. >> >> Here is an example of a forest multipolygon, imported by me >> (canvec_fsteggink). It is still version 1, but it has tags on the relation, >> not on the rings (except for the quarries): [2] >> This is from Canvec v7.0. IIRC, we started at v6.0, and the last version >> I know of is v10.0. Maybe v6.0 had wrong tagging, but I'm not seeing any >> such cases in the OSM inspector. >> >> So, I'd like to ask you to give a couple of examples where data imported >> from Canvec is clearly wrong with regard to old style multipolygon tagging. >> When we have clear examples, then it might be easier to come up with a plan >> how to fix it. But so far, I see absolutely no reason why Canada stands out >> in a negative way. Yes, we all acknowledge that Canvec data is suboptimal, >> but as others already have pointed out, mapping everything by hand in >> especially remote areas is nearly impossible. >> >> Regards, >> >> Frank >> >> [1] http://tools.geofabrik.de/osmi/?view=areas >> [2] https://www.openstreetmap.org/relation/1481163/history >> >> On 30-06-2017 09:52, Jochen Topf wrote: >> >>> Hi! >>> >>> A week ago I wrote this email and nobody answered it yet. Does that >>> mean that nobody feels responsible for the import that created this data >>> and nobody here cares for this data? >>> >>> I see three ways forward: >>> * We do nothing. The broken data stays in OSM. Not a good solution, >>> because every user of the data has to work around this or handle the >>> complaints. >>> * The Canadian community steps up and fixes the data, automatically or >>> manually. >>> * We ask the Data Working Group to remove the broken import. >>> >>> Jochen >>> >>> On Thu, Jun 22, 2017 at 11:38:15AM +0200, Jochen Topf wrote: >>> >>>> Date: Thu, 22 Jun 2017 11:38:15 +0200 >>>> From: Jochen Topf <joc...@remote.org> >>>> To: talk-ca@openstreetmap.org >>>> Subject: [Talk-ca] Multipolygon problems >>>> >>>> Hi! >>>> >>>> In the last days the OpenStreetMap Carto Style 4.0 is being deployed on >>>> the OSMF tile servers. This new version of the style doesn't take >>>> old-style multipolygons (where the tags are on the outer ways instead of >>>> on the relation) into account any more. In a huge effort in the last >>>> months we have converted all old-style multipolygons to the modern >>>> tagging, so this is a good step! >>>> >>>> Unfortunately, as a side-effect of this change, many multipolygon >>>> relations now appear wrong on the map. This is the case for multipolygon >>>> relations that have the same tags on the relation as well as on (some of >>>> the) outer or inner ways. This is *wrong* tagging, and needs to be >>>> fixed. (Note that this always was wrong tagging, even before we >>>> deprecated old-style multipolygons, but the way the software worked with >>>> old-style multipolygons, this problem was not visible on the map. But >>>> now it is.) >>>> >>>> Here is an example: http://www.openstreetmap.org/relation/1330741 . As >>>> you can see (unless somebody fixes this :-) the clearing in the forest >>>> that should just have grass, also has tree symbols on it. In many other >>>> cases it is not this obvious, there are just islands in a river missing >>>> or so. >>>> >>>> There are about 50,000 cases like this worldwide, forests, waterways, >>>> all sorts of areas. But the worst problem is in Canada. There are about >>>> 15,000 affected relations, most from the CanVec imports. >>>> >>>> First, we have to make sure that there are no further imports of broken >>>> data. I hope the people who have done those imports (and might still >>>> continue) are here on this mailing list. If not please make them aware >>>> of this issue and/or put me in touch with them. Second, somebody needs >>>> to clean up the broken data, either automatically or manually. 99% of >>>> the data has not been changed since the import, so it might be feasible >>>> to do an automatic cleanup, but somebody has to do this. Otherwise we'll >>>> have to do a manual cleanup, through tools such as Maproulette and the >>>> OSM Inspector. I am currently in the process of creating Maproulette >>>> challenges for other areas of the planet, but will not do this for >>>> Canada at this time. Lets discuss this here first. >>>> >>>> I can provide OSM data extracts, statistics, etc. if somebody wants to >>>> look at the data. >>>> >>>> All of this is part of a larger effort to fix areas in OSM. See >>>> http://area.jochentopf.com/ for more information. There is also a >>>> thread >>>> on the talk mailinglist at >>>> https://lists.openstreetmap.org/pipermail/talk/2017-June/078203.html >>>> and this issue >>>> https://github.com/osmlab/fixing-polygons-in-osm/issues/36 . >>>> News of the effort are posted regularly to >>>> https://github.com/osmlab/fixing-polygons-in-osm/issues/15 . >>>> >>>> Jochen >>>> -- >>>> Jochen Topf joc...@remote.org https://www.jochentopf.com/ >>>> +49-351-31778688 >>>> >>>> _______________________________________________ >>>> Talk-ca mailing list >>>> Talk-ca@openstreetmap.org >>>> https://lists.openstreetmap.org/listinfo/talk-ca >>>> >>> >> >> >> _______________________________________________ >> Talk-ca mailing list >> Talk-ca@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/talk-ca >> > > _______________________________________________ > Talk-ca mailing list > Talk-ca@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-ca > >
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