[Imports] Norwegian place name registry (SSR)

Thomas Hirsch Thomas.Hirsch at kartverket.no
Mon Jul 15 06:16:50 UTC 2013


Hi Jason -

I hope it's ok if I CC to the mailing list, it sounds like you intended to post there.

> - Use the semicolon separator on alt_name to get all of your alternate names in.

Ok, that would be a better option to what Karl Ove suggested. I was just uncertain because a lot of renderers do not interpret semicolons in name and basic type tags. But I guess it's the renderers which should learn.

> - You should definitely use offical_name tag in addition to the name tag. [...] and we can correct them via the name tag, leaving the offical_name alone.

Sounds like a plan.

> - 900.000 points is a lot of points, I think you need to get some automation going. How long do you think this import is going to take given the current team size?

I was able to conflate 4k in four days, tracing complex geometries (lakes, rivers) along the way. That was in a kommune with good aerial coverage.
Yes, 900 person-days are a lot of work, but at the same time, this will seed 900k of the most important places in the country (most of them are not on the map at all), so I think it's best to establish the procedure and allow people to map the features at the same time. It's a big difference motivationally whether you are tracing millions of lakes in the Norwegian hinterland, or whether you suddenly are tracing named bodies of water in the mountains. ;)

We haven't had a proper hand count for the team size yet. If we reach ten people, it may be ninety days. If we stay at two it's an open process. Anyway, in areas of missing or low resolution aerial coverage, not all names can be imported, unless as a node (or note), so the process will continue/repeat every time the coverage improves.

> - Have you tried using the conflation plugin with some test data, I am not sure how well it will work for this application.

We are in process of testing the conflation plugin, and I have a few API scripts adapted to the task which identify candidate features and allow to conflate. (https://github.com/relet/ssr) We will evaluate what works best for us.

> - Are you sure the factsheet URL is going to be stable?

I'm a bit worried about it. It should, and the people behind it are aware of the issue, but you never know about the next generation. Linked open data is not a well-established concept in people's heads. Then, if nothing breaks when URL change, change remains acceptable.

> - how accurate are the source positions? If they are very accurate, say < 4 meters, then the automation will be easy. If the uncertainty is 150 meters, its is going to be a lot work regardless of how you do it.

The positions are very accurate.

> - Just an FYI, we did a similar import in the US. http://wiki.openstreetmap.org/wiki/GNIS

Thank you so much! I had been looking for how imports (and more importantly, continuous synchronization) are handled in similar cases. If I understand correctly, GNIS is not updated, or does the survey group just have no means to identify outdated names?

If anyone has good examples for how continuous imports/geosynchronization are handled as opposed to one-time imports, I'd be very curious about that.
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