Hi all, new to the openstreetmap community but been a map editor for some time. I am more of an armchair mapper which I’ve learned is not always looked at with the highest regard . That being said, I am intimately familiar with the West Parry Sound area, especially with the town proper.
I am currently embarking on the task of digitizing the building footprints and adding civic addresses to each. When I started, only the main ‘downtown’ and larger buildings were represented. This is likely due the outdated methods for CanVec buildings based on <1980 imagery digitization. Along the way, I have also updated road centrelines, road names, fixed some land cover issues etc.
I am also learning more about the imports of CanVec data which for my area I agree with the larger community that it is severely outdated and not accurate to the current condition.
I would love to have my general process of building digitization and addressing reviewed:
I use the ESRI basemap to digitize buildings. For the Town of Parry Sound, this is 2018 COOP imagery from the Ontario Imagery program, when zoomed into a small enough level. The 2023 imagery is likely to become public domain ‘soon’ from the province, including public REST access.
I have some experience recognizing the offset of building corners from imagery not taken straight-on from above, and do my best to accommodate that, and work around any tree cover.
I use the following tags to improve the information (this is the part I most need reviewed)
addr:city=Parry Sound
addr:housenumer=*
addr:province=ON (I was using ‘Ontario’ for some, but am working on fixing this mistake)
addr:street=*
building=* (house, apartment building, terraced)
house=* (detached)
source=local knowledge;aerial imagery (this is where I wonder if I should even be including this tag. In this area though, I thought it important to distinguish that the information is not from CanVec.)
I try to complete one road at a time, which going forward will include removing the address interpolation.
I have already removed address interpolation where I found it was completely wrong (wrong side of the streets marked odd/even, only representing one address #, in an area where the addresses could not be interpolated etc.)
I would use a guide to align buildings along the street front as I saw recommended in the OSM wiki, but in this area with a wide variety of build dates, that is not reasonable.
Some other things I have been doing, is removing the source=CanVec 6.0 where I have improved or changed the information. I am in need of feedback if that is appropriate and doesn’t affect potential future imports?
I would appreciate any feedback about this process, and to connect with any possible mappers in the area of Parry Sound, Muskoka, or Killarney for any consensus needed in the area. Happy to discuss and improve my process, including any mistakes I’m propagating, or any additional information I could be adding.
Generally, I’ve heard the addr:province tag is not needed because the buildings fall inside the provincial relation. The same would apply for the addr:city tag if there is a relation for the city.
The source tag is not needed for each building as that info is applied to the whole change set whenever it gets saved and uploaded.
Hello ps_mapper, this mostly sounds great! Thank you for your contributions!
Just for clarity, how are you getting the house numbers that you are adding? Manually walking down the street, or from the address interpolation (e.g. there’s 4 houses on a block with an interpolation 2 to 8 Some Street), or some official data source?
I agree that addr:province tag is not needed except in truly exceptional cases. addr:city is mostly not needed too (if the building is within the currently-mapped boundaries), but won’t hurt too much.
First up, I would specify which imagery, rather than just putting in “aerial imagery”.
Generally, I don’t put source tags on newly added or edited buildings, and I remove it when I edit substantially. The source tag on data is generally an old scheme. Do put source for the entire changeset, though (as you’ve been doing). That way, we can check object history to see when it was created or edited, and read the source there.
I make exceptions when it’s necessary for communication about one or a few specific features: that this building, contrary to others in the area, is mapped from a specific imagery, or is approximated from ground-level survey. But if you’re going through and editing entire street or town, we don’t need to have that mentioned on each building.
great, thanks for clarifying. I will be incorporating all this advice going forward and I’ll go back and do a clean-up changeset to take care of the discrepancies and roll back some of the excess information.
Before you use any of the data, you must get the license approved.
Sending an email to the LWG to the email listed on this page: Contact - OpenStreetMap Foundation will get you in touch with the right people
thanks for the insight. It seems like quite a sticky situation with the government licenses.
I will be submitting the license for review.
Also to aid this I did go back and bike the streets I have edited and some I plan on editing soon. I took notes to highlight any differences between my edits and street-level and there were none! As far I can tell, I haven’t downloaded, lifted or otherwise copied the property of The Archipelago, being the points and other affiliated data more than what one could gather at street level so I’ll keep what I’ve edited so far, and do better reconnaissance going forward.
How are you planning on telling the difference between house=detached and house=semidetached? It is difficult to tell between the two with 15cm aerial imagery.
I suggest using house=yes for all houses or houses you are unsure of. Another possibility is surveying houses but this is extremely time consuming/.
. That being said, I am intimately familiar with the West Parry Sound area, especially with the town proper.