[Talk-ca] Building Import

Jarek Piórkowski jarek at piorkowski.ca
Tue Mar 26 17:45:41 UTC 2019


On Tue, 26 Mar 2019 at 13:10, Begin Daniel <jfd553 at hotmail.com> wrote:
> There is actually no standard “code” available since I use FME (www.safe.com). It is a proprietary ETL application and all operations are done using “transformers” (https://www.safe.com/transformers/). I can provide you with the workbench I developed (a bunch of linked transformers) but you need a license to run it. This is why I tried to describe the operations I run on the data in the wiki.
>
> As you did, people may send me coordinates (bounding box) of an area they know well. I’ll process the area and send the results back in OSM format. Please, be reasonable on the amount of data to process ;-)

Thanks Daniel. Let me know how it looks then!

Coming from an open-source background, the process is unusual to me,
and I have questions about scalability - will you be able to process
and provide updated data files for all of Canada then? - but if others
are comfortable with it then I won't object.

Some general thoughts regarding tooling as raised upthread:

I was initially excited to see building footprints data as they help
two quite distinct purposes:

1. they provide a mostly-automatic source of geometries for the
millions of single-family houses that wouldn't be mapped in the next
decade otherwise

2. they might provide a corrected and fairly accurate source of
geometries in heavily-built-up areas, where GPS signal is not that
reliable and it can be really difficult to get sufficiently accurate
geometries from imagery, whether because it's not sufficiently
high-resolution, two sets of imagery with conflicting offsets (Bing
and Esri are the two best sets in Toronto, and they're off by about
1-2 m on north-south axis from each other - that's not something I can
check with a consumer-grade GPS so I'm left guessing as to which is
true), or non-vertical imagery (I can count the floors on supposedly
top-down imagery in some cases).

>From what I saw, imports in the GTHA initially focused on the first
case, and I think the Tasking Manager setup was mostly sufficient for
those - where there is nothing currently on the map, or a few simple
2D geometries, a 4 sq km area can feasibly be done in under an hour.

However, as raised by others, I would really want the working squares
in Old Toronto for example to be no more than 500 m x 500 m, or no
more than 1 km x 1 km in St. Catharines. I would _love_ to have the
geometries to manually compare and adjust the 3D buildings already
existing in the area, but it will be much slower.

--Jarek



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