[Talk-ca] [Import] Ottawa Buildings & Addresses [Statistics Canada project]

[Steve Singer]

On Wed, 19 Oct 2016, James wrote:

> Seems like a good enough time like any other to talk about the import of Ottawa buildings and addresses
> into OpenStreetMap.
> 
> Documentation is available here:
> https://wiki.openstreetmap.org/wiki/Canada:Ontario:Ottawa/Import/Plan

A few comments

* Replacing Building Geometries - I don't like the policy of replacing 
existing building geometries with imported ones.  I feel that large scale 
replacement of hand traced work with automated/imported work will discourage 
future mappers.  Also sometimes which is 'better' is a matter of opinion and 
if a few mappers are replacing hundreds or thousands of buildings in a short 
period of time it is hard to have discussion on an individual building 
basis.   I don't have issues with a mapper manually changing or replacing 
the geometries but the bulk non-traced nature concerns me. I have 
heard numerous complaints over the years from mappers who traced lakes 
manually only to see them replaced by canvec imported lakes.

* Notes - How many 'What is the address of this house?' notes do we think 
this is going to generate? Adding a few dozen notes in the Ottawa area isn't an 
issue but if this process adds hundreds of notes that require manual survey 
then I'm not sure that is better than just skipping the address(but 
this could be discussed)

I think the import plan needs to talk more about what the expected 'quality' 
is. I am not talking about the quality of the data but the quality of the 
merging

For example:
* Do we expect that before uploading a tile all JOSM validator errors get 
cleared on the objects being uploaded?
* If an existing object such as a road, alley or stream runs through the 
geometry of the building then will the pre-upload validation process require 
that this be fixed


Part of the problem with the Canvec imports is that quality is very much a 
factor of who imported a tile in a particular area.  We never really came up 
with minimum standards for the validation and repair requirements. I think a 
checklist of specific types of problems that we expect will need 
correcting/validating by the person uploading the tile would help


The plan also talks about using post upload validation tools like Osmose.

Is the proposed workflow something along the lines of
1) Grab a .osm tile with buildings
2) Work in JOSM to address any issues the importer finds by eyeballing 
things or using the validator
3) Upload
4) Pick another tile repeat
5) Once there are no more tiles left check Osmose and other tools

I think it would be better to fix all the issues with the footprints in the 
first tile before moving onto a second tile.

Are there examples of tasking manager coordinated building imports that the 
community considers a success? If so how does this plan compare to what has 
worked well. (This isn't specifically directed at James)



I haven't yet looked at samples of the .OSM files


Steve



> 
> Discussion with local mappers has happened in person for multiple months(community buy in is very high in
> these meetings and we all saw benefit in including this data) :
> https://www.meetup.com/openstreetmap-ottawa/
> 
> Once positive discussion of a period of 2 weeks has been met, we would like to start the import of said
> data.
> 
> Thank you.
> 
> 
>