Hi, You will probably find that there is a statutory instrument that defines much of the EEZ boundaries. Certainly the boundary between England / Wales and Ireland is defined (by agreement) via a series of straight lines along longitude and latitude. This would avoid using calculated mid-points. Something like this. http://www.askaboutireland.ie/_internal/gxml!0/2ocqn930ubywvi8z0wl9dhefnm6z926$nh3h5o3m557b9ec4auqqpuref4xzb5a Similarly, the western boundary is, I understand defined by a statutory instrument. This would avoid using calculated mid-points. AFAIK, the boundaries with Northern Ireland and Scotland are not agreed, so it's down to using mid-points. I think islands should be included within the EEZ - its all the one territorial claim - as islands change in size. What is the OSM standard for this? Colm --------------------------------------------------------------------------------------------------------------- Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. Margaret Mead
> From: talk-ie-requ...@openstreetmap.org > Subject: Talk-ie Digest, Vol 76, Issue 5 > To: talk-ie@openstreetmap.org > Date: Fri, 18 Sep 2015 12:00:11 +0000 > > Send Talk-ie mailing list submissions to > talk-ie@openstreetmap.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.openstreetmap.org/listinfo/talk-ie > or, via email, send a message with subject or body 'help' to > talk-ie-requ...@openstreetmap.org > > You can reach the person managing the list at > talk-ie-ow...@openstreetmap.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Talk-ie digest..." > > > Today's Topics: > > 1. Ireland EEZ boundary (moltonel 3x Combo) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 17 Sep 2015 14:47:40 +0200 > From: moltonel 3x Combo <molto...@gmail.com> > To: talk-ie <talk-ie@openstreetmap.org> > Subject: [OSM-talk-ie] Ireland EEZ boundary > Message-ID: > <CANQow5+f8ubTShQS=bbtjhstb80w6o_4splvzwdboqszm9f...@mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > Hi, > > the EEZ boundary is a maritime exclusive economic zone. It is mapped > as relation 4121287 in OSM: > http://localhost:8111/import?url=http://www.openstreetmap.org/api/0.6/relation/4121287/full > (using a josm/mercator remote-control link instead of a website link > because the website is likely to timeout). > > There are a few problems with it: > * At ~4000 members, it is enormous. JOSM validator takes over a minute > to check it on my machine. It's the biggest relation we have, even the > four regions are about half the size. > * It only has a fraction of the islands it ought to have, and most of > those are mistakenly tagged as outer instead of inner. > * It keeps breaking (non-closed ways), and the more members a MP has > the more laborious it is to fix it. > > What should we do with it ? Either... > > a) Add all the missing islands, fix their roles > pros: that's the best theoretical way to map a maritime area > cons: will exacerbate all the size-related problems > > b) Keep as-is but drop all the islands > pros: reduces the size strain a bit > cons: not a true maritime area anymore. Boat navigation will surely > not get fooled by this, but other tasks like for example area > calculation gets more complicated. > > c) Same as b) but follow the ROI-NI border instead of the coastline > Same pros and cons as b), only stronger > > d) Only keep the maritime ways > pros: simplest version > cons: not much can be done with it appart from rendering (for > example a bot can't determine wether it is navigating within the EEZ > anymore) > > e) Use multilinestring relations to simplify the geometries > pros: great reduction in member count. Same technique could be used > to simplify the other county and region MPs > cons: not all tools support multilinestring relations (what about > nominatim ?), they are used in France for example but are not yet a > standard osm feature. Islands still need to be supported, as in a). > > > > I'm leaning towards solution c), but could be convinced of either. > What do ye think ? > > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Talk-ie mailing list > Talk-ie@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-ie > > > ------------------------------ > > End of Talk-ie Digest, Vol 76, Issue 5 > ************************************** _______________________________________________ Talk-ie mailing list Talk-ie@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ie
