[Talk-ca] NRC building footprints - from lidar

[Tim Elrick]

Hi all,

All those new sources are really exciting! Thanks for making us aware of 
the data, Keith!

I just checked the NRCan LiDAR building footprints for Montreal [1]. 
Unfortunately, they seem to have the same flaws as the Microsoft 
building footprints. The data quality for Montreal cannot keep up with 
the building footprints in the Open Building Database released by 
StatCan - it probably has to do with the altitude the LiDAR sensor was 
flown over the surface, as the OBD data for Montreal was also derived 
from LiDAR (but probably flown at a much lower altitude, hence a much 
more detailed result).

As with the Microsoft building dataset the NRCan data set is probably 
useful for emergency services and desaster relief organisations that 
only need to know the existence of buildings in an area, but not the 
exact shape. I doubt it can be used for import into OSM, however, as 
already stated in another e-mail, in remote areas it still might be good 
enough - I guess, it all depends on how you read the 'ground truth 
principle' and other 'mapping rules' in the OSM cosmos.

Like Pierre, Daniel and Nate have shown for the OBD data the NRCan data 
should at least be simplified and orthogonalized if deemed appropriate 
for importing.

Cheers,
Tim

[1] https://imgur.com/a/4eKDpcj

On 2019-04-27 09:56, keith hartley wrote:
Hi all,
Canadian Geomatics posted this data set a few months back from Natural
Resource Canada.
It's Building footprints from Lidar or high res imagery.
https://canadiangis.com/automatically-extracted-buildings-canadian-open-data.php?fbclid=IwAR22SaWwz7--LarDksVfcQuZ9RDgkVc421n9saJ_Lv8r6xq1qPSrouEF0Ww

https://open.canada.ca/data/en/dataset/7a5cda52-c7df-427f-9ced-26f19a8a64d6

  From what I can tell when placing the data over imagery it's very bang
on. Highly accurate, good shapes (unlike the bing files) and well
placed. As far as I can tell no one else has uploaded these to OSM. The
areas in manitoba are mainly where there's little to no other building
info.
I can write an upload plan on Manitoba wiki as the data is complaint
license wise. Anything else I should be looking for? The local mappers
here are pretty excited about it.

Keith




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