[NUUG kart] Importing GNS data for Svalbard

Gustav Foseid gustavf at gmail.com
Tue Oct 7 12:24:54 CEST 2008

2008/10/6 Mike Collinson <mike at ayeltd.biz>

>  Gustav, thank you for your kind feedback.  All gone now except island
> names.  May I ask about your experiences with quality?  Was the problem just
> positional accuracy or did you find substantial errors in the names
> themselves?

The main problem was positional accuracy, combined with the large number of
small (close to irrelevant) place names. For many of the names we had
knowledge, or could easily check, most names were misplaced.

When we combined misplaced names, with the fact that many names were for
very small places like farms, rocks and houses, they were of little or no
use. You would need very detailed knowledge to be able to correct these
names. I looked at the farm names around where I grew up, and had not heard
about half of the names. Trying to correct the position, or even verify that
the name was in fact still in use, would be impossible. Another example was
a rather small area off the coast of Troms, where around 60 named rocks
would have to be verified.

For administrative names (kommuner), the names in GNS was old and was no
longer correct. Other names also had archaic spelling.

So, we basically ended up with a map where large areas were filled with
names we knew were wrong, but with no way of correcting. Keep in mind, that
we are acouple of handfulls of mappers, and the GNS file for Norway contains
84.000 names. That is approximately 10.000 names for each mapper to verify.

Our conclusion is that importing the GNS data would ruin OpenStreetMap as a
source of reliable geographic information in Norway.

For Svalbard, the data looks more accurate. At least there are a number of
digits in the latitude and longtitude, but also here the data suffers from
unknown quality. There are also a few examples of the same name being given
in different languages or spellings (the worst example I found is South Cape
Islands, Syd Cap Æerna, Sydkapholman, Sydkapøerne, Sørholmen, Sørkapholmane,
Sørkappholmane and Sørkapøyane, which seem to be the same islands). I wish
we had known more about what sources are used to collect these data.


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