[Talk-ca] FW: Re: Importing buildings in Canada

[Nate Wessel]

Responding to point C below,
I would strongly suggest that we not confuse the process of importing 
new data with that of updating/modifying existing data in the OSM 
database. One of the things I really disliked about the initial building 
import was that it overwrote existing data at the same time that new 
data was brought in. These are really two separate import processes and 
require very different considerations.

We can certainly consider using this dataset to improve/update existing 
building geometries, but I think that is a separate process from the 
import we are discussing here. To keep things simple for this import, I 
would suggest removing any building from the import dataset that 
intersects with an existing building in the OSM database. That is, let's 
not worry about conflation for now, and come back and do that work later 
if we still feel there is a strong need for it.

I see the main point of this effort as getting more complete coverage - 
it we want to use the dataset to do quality assurance on existing data, 
that is a whole other discussion.

Best,

Nate Wessel, PhD
Planner, Cartographer, Transport Nerd
NateWessel.com <https://www.natewessel.com>

On 2020-01-15 12:55 p.m., Daniel @jfd553 wrote:
>
> Thanks for the quick replies!
>
> Now, about...
>
> *a) Data hosting:*
>
> Thank you James, I really appreciate your offer (and that of others). 
> So yes, I think hosting pre-processed data in the task manager, for 
> approved regions, is an attractive offer. When we agree on a 
> municipality for pre-processing, I will contact you to make the data 
> available.
>
> BTW, I thought ODB data in OSM format was hosted with the OSMCanada 
> task manager. I understand that ODB data are currently converted on 
> the fly when requested?
>
> *b) Task manager work units for import:*
>
> I agree with Nate, ~ 200 buildings or ~ 1,500 nodes would be suitable. 
> I was thinking at the same importation rate, but for an hour of work. 
> It seems best to target 20-minute tasks.
>
> *c) Task manager work units for checking already imported data*
>
> According to Nate, it is definitely not faster than actively 
> importing. We should then keep the above setup (b).
>
> However, what if I add a new tag to pre-processed data indicating if a 
> building was altered or not by the orthogonalization (and 
> simplification) process? For instance, /building:altered=no/, would 
> identify buildings that were not changed by the process and that could 
> be left unchanged in OSM (i.e. not imported); /building:altered=yes/ 
> for those who were changed by the process and that should be imported 
> again. The same pre-processed datasets could then be made available 
> for all cases. Thoughts?
>
> *d) Finding local mappers:*
>
> I agree with Nate’s suggestion to try contacting the top 10 mappers in 
> an area. Using the "main activity center" would work for most of the 
> contributors but selecting other overlays (.e.g. an activity center 
> over last 6 months) could also work great. As long as we identify who 
> might be interested in knowing there is an import coming.
>
> Comments are welcome, particularly about the proposal on c)
>
> Daniel
>
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