[talk-au] National borders

[Paul HAYDON]

Hi Michael,

I'm keen to read up on the process, so that I learn a little more about the mapping workflows on OSM. And happy to help, so let me know if I can be of any assistance.

BTW, won't the bays be self closing during buffer creation (if the mouth is less than the offset)?


Cheers,
Paul.

-----Original Message-----

From: Michael Krämer
Sent: 21 Sep 2012 17:24:23 GMT
To: Ian Sergeant,Talk-AU OSM,Paul HAYDON
Subject: Re: [talk-au] National borders

Hi,

finally I got the process sorted out to generate a border from
natural=coastline, natural=reef and the baseline segments. The resulting
osm-file can be found at [1].

Using the dataset I also updated the picture from the post below to show
the differences [2]. It doesn't look that bad everywhere but especially
along the Queensland coast that's not the only place like this.

So no my question is how we should move on from here. I see different
options:
- Upload the dataset "as is"
- Try to get it better e.g. by
     * manually by adding baseline segments (close bays, low water)
     * do a more accurate buffer computation
     * trace more reefs from Bing
     * ...
- dump the idea and look for a better one
- ...

BTW this time I've taken notes so if anyone is interested I could share
the process I've used. The processing hasn't been too acurate given the
limitations of the data. Especially I used a buffer of 0.2 degrees
instead of exactly 12 nautical miles so the distance is always a bit too
short.

Michael

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[1] https://dl.dropbox.com/u/3882550/OSM/NationalBorder.osm.bz2
[2] https://dl.dropbox.com/u/3882550/OSM/ComputedCoastline.png