[OSM-talk] Coastlines

Joerg Ostertag openstreetmap at ostertag.name
Wed Mar 22 09:42:05 GMT 2006

On Wednesday 22 March 2006 10:29, Immanuel Scholz wrote:
> Hi,
> > And it would be great if I don't have to download from 1000 different
> > sources to get all the Data needed to draw a complete map.
> I'm sorry, I used the wrong words.
> I don't want to force the users to download from different sources too.
> But the server can ;-).
> As example, background tiles currently aren't hosted on the OSM server.
> They are fetched on demand from a WMS server. My idea was, that other
> people host the coastline database (because they have better data formats
> to do so) and the server only imports rendered pictures or maybe read-only
> vector data of the required area.
> But if the coastline accuracy data isn't good enough, it may be better to
> completly import it into OSM format so that people can start correcting
> it. I still think we should seperate the database for this and the real
> street data in the long term..

As of my tests the coast and Border Data was good for an overview, but not 
accurate enough to really show a detailed map.

> > I don't see any obvious reason why the current Data structure cannot
> > easily hold coastlines, river lines and city boarders besides pure street
> > information.
> The main difference of coastlines is, that they are stored and transfered
> in a way where the precision of the data increases with the detail level
> you require.

I think every software using data from OSM has the same problem with 
displaying streets in an overview Map. So there is no difference to the 
street part. I think it would be easiest to just store the most exact version 
of streets, coastlines, rivers, ...  and let the user-software combine points 
which are too close to display as separate points. Any user software has to 
import the data into it's own structure anyhow.



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