> From: David Groom [mailto:revi...@pacific-rim.net] > Subject: Re: [Talk-ca] Clean up - natural coastline > ----- Original Message ----- > From: "Andrew Allison" <andrew.alli...@teksavvy.com> > Subject: [Talk-ca] Clean up - natural coastline > > > > Hello: > > I'm in the process of recreating non-ct data. > > > > Any gotchas that I should look out for in replacing coastline data. > > 2 main ones - > > A) direction ( see below), > > B) coastline ways when taken together should always form an unbroken > line > around a land mass. > > minor "gotchas" > > C) the coastline import from PGS caused a number of small "artefacts" > to be > created, (many 3 node triangles of coastline appearing). These are not > true > coastline, so need to be dealt with. > > D) In places the coastline import was run over an area which was well > inland > of the true coast. The import found water bodes (lakes and rivers) in > these > areas, and created them as coastline. When recreating these ways it > would > make sense to tag these correctly. Note very large lakes may still have > to > be tagged as coastline however. > > Note, that a lot off C & D's I have tried to clear up over the last few > months, but I'm still working through them. > > > > > Pros and Cons of shorter ways. > > Some of the PGS imports have created very short ways (I've come across > whole > km of coastline made up of many 2 or 3 node ways) > > In general when I've been tidying coastlines I've tried to join any > sections > of coastline less than 40 nodes. > > Similarly I've come across some very long ways. In general (and its a > personal view which I don't always adhere to myself) I don't like ways > which > are longer than 1,000 nodes. > > > > > Does direction matter? > > YES YES YES. Coastline ways MUST be drawn with the water to the right. > > > > > How often is coastline data updated? > > Do you mean, "how often is the coastline file used to render the coast > on > the Mapnik layer" updated. The answer is periodically, but generally > every > 4 - 6 weeks > > David > > > > > > Hope I keep every bodies feet dry and I don't damage something and > find > > out next month that I messed up big time. > > > > Or don't bother "we" are working on that :-) > > > > > > Andrew > > aka Purple Mustang. > >
I've worked out how to get the GeoBase NHN coastline into .osm format and plan to work on the west coast. The PGS is low resolution and there's no other data for most of the area. I don't want to import CanVec, partially because of the extensive coastline cleanup work required to import it properly, partially because I don't see that it adds value importing all of CanVec in an area where it won't be maintained. _______________________________________________ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
