Hi,
as my first reply didn't go to the list but directly to Frederik here a
second try:
Am 15.05.2012 16:50, schrieb Frederik Ramm:
I noticed that of all 193 UN member states, there's only one for which
we don't have international borders in our database (instead, a node
tagged place=country). That country is Tonga in the South Pacific.
Yes, there's quite a bit left to map in the South Pacific.
I have taken our existing Tonga coastline and computed a 12nm buffer
around that (after having read on the CIA world factbook that they have
a 12nm territorial waters claim), and prepared the following file with a
boundary relation that we could use to replace the country node:
Well, this is probably the best we can get for the time being. In a
perfect world we wouldn't use the coastline but the baseline. The
baseline definiton ([1], §5+6) closes bays by straight lines which makes
a difference given the shape of the islands.
But manually deriving the baseline using Bing imagery would be a rather
complex task. So unless there's a decent way of doing this by some fancy
software package I think there's no way of getting the basline.
So I think using the coastline is fine. But I would suggest to add a
note to the data somehow along the lines of "only approximate, base on
coastline".
http://www.remote.org/frederik/tmp/proposed_tonga_boundary.osm
After looking at the data I think you missed some islands that have
quite an impact to the border. I did some checks with Wikipedia (also
adding a few names) and found the follwing ones (with Way ID)
ʻAta (22383999)
Tokū (22390574)
Fonualei (22390195)
So if you don't mind, I would ask you to add these.
I'm not 100% sure if my reasoning is correct; there is the case of the
Minerva reef which lies about 200km to the SW of Tonga and I read that
Tonga lays claim to that - but, as far as I understand, only EEC claim
and not territorial, so I guess it is correct to not include it in the
country boundary.
I agree. From what I understood the reef is submerged so I don't think
it's possible to establish a territorial claim. But I'm also not
completely sure about this.
I'm not normally in favour of doing imports but seeing that Tonga is
really the "odd one out" in the list of countries, maybe it is worth the
effort to fix that.
I think that an import makes perfectly sense for boundaries, especially
maritime borders. They hardly can be mapped on the ground.
Michael
[1]
http://www.un.org/depts/los/LEGISLATIONANDTREATIES/PDFFILES/TON_1989_Act.pdf
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