[OSM-talk-be] Agiv import

[Sander Deryckere]

2016-01-25 15:37 GMT+01:00 Glenn Plas <glenn at byte-consult.be>:

> On 25-01-16 14:06, Marc Gemis wrote:
> > * We pass this somehow through the import mailing list ( I fear we
> > cannot avoid this). Sander, you have some experience with this. What
> > do you think ?
>
> This needs to pass indeed, but let's not call it an import from now on.
>  I prefer a "semi-automated, human reviewed, merge operation" :)
> It is a bit like the news calling it a "tactical bombardment" when
> blowing up bombs, the first almost sounds like there aren't any
> casualties at all.
>
> I'm confident we'll get through it even when calling it an import. The
data quality is good, we're with a limited set of active mappers (who
worked on OSM long before trying an import), and we care about our region.

The only thing I'd have to defend is the usage of the GRB. They'd need some
guarantee that the key is valid (won't change without a reason, and won't
be reused on another building). I guess the AGIV gives some guarantee for
it in their documentation, but we should make the clear.


> > * We have a face-to-face meeting / hangout to explain the procedure to
> > interested people.  Face-to-face is better I think, but might not be
> > feasible for everyone. Perhaps a combination ?
>
> I believe face-2-face is better, and I'm willing to spend time on this,
> there are many questions you will have and the interactive approach will
> be easier to answer/demonstrate instead of describing it.
>

Face-2-face sounds good.

>
> > * We start "the import". Somehow we need an overview for this to see
> > who is working on a certain town. (a shared document/spreadsheet)
>
> I don't think you really need that in order to be able to work (it
> wouldn't hurt though).  Version management will take care of people
> working on different areas, in case of conflicts (I had a few where
> buildings where updated after my data retrieval from OSM and before
> uploading changesets) it's not fun resolving those in JOSM (even hard
> sometimes).
>
> So I would suggest doing it in small fractions. I tried 'finding'
> building hotspots and just work square per square.  You can also to the
> 'bijgebouwen' first and then later the main buildings, after that
> garages and so on...  So it doesn't have to be segregated into area's ,
> you could just do subsets.
>

Yes, it should be organised in a way you can do an hour or two work on it,
upload it, and return later on with fresh OSM data to avoid conflicts.

>
> The only thing you need to keep track of is the work you've done
> yourself.  I deleted the buildings from the source file once I moved
> them to the target layer, to avoid duplicate validation work.
>
> We could set up a map for this. You can overlay mapbox vector tile
buildings with a GRB background, and see where any GRB buildings stick out,
or the other way around.

We can also use overpass to do some counting in squares or boundaries. F.e.
in Overpass, it would be easy to extract a list of all GRB ids of buildings
in a certain municipality, and compare that with the official data.


> The area size was not always as large, it depends on the concentration
> of buildings.  We should discuss this at the meeting, because I'm just a
> one man show and would love some peer input and feedback.
>
> I was thinking about using HOT osm task manager, it's code is available.
>  That would be awesome to
>
> https://github.com/hotosm/osm-tasking-manager2
>
> Then there is also the matter of downloading (Aka `Ordering`) the data.
> We should do this 'at once' preferably to make sure adjacent areas match
> up. Not doing so might give some problem at the borders of the area.
> But that should be minimal.
>
> There are 307 'gemeentes' / general area's in the selection list.  You
> can combine some, but I haven't tried to combine all for a full download.
>

I ran into the problem of not being able to download it all. My internet
connection isn't stable enough, and when the connection drops, the download
can't be resumed.

But even when you're able to download everything, you should still be able
to split the shapefile. Not all shapefile splitters will work, as some just
run in your memory (and I guess you don't have more than 15 GB RAM).

OSM tasking manager indeed seems like a good idea (it's also used by other
countries to organise imports), and the tasking manager can even provide
links to external files in some way (I've used it when doing an import of
names in Sierra Leone once).

>
> Glenn
>
>
Regards,
Sander
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