Hi,

Could someone make a revert here at Tonga Island, its seems that some gates and ways are at the right place, but a lot of fences and houses are out of place. Compared with DigitalGlobe Premium Imagery. https://www.openstreetmap.org/#map=18/-21.09995/-175.33821&layers=N I am not used to start a revert.

Greetz

asked 30 Mar, 21:34

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Hendrikklaas
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Are there any GPS traces for the roads?

(01 Apr, 00:39) InsertUser

An example node that is offset is https://www.openstreetmap.org/node/3233951970 . That was added in 2014, apparently using Bing imagery, and has not been moved. It is offset according to current Bing imagery. All current imagery agrees about the offset, so presumably the older Bing imagery was wrong.

This unfortunately is the danger of using only imagery to add lots of detail - there's lots of work to do to fix the wrongly-added detail afterwards. Also, it's not simply case of selecting everything and moving; the offsets of different features seem to vary.

What I'd do before doing anything else is try to get a number of north-south and east-west GPS tracks in place (if you're not local talk to someone who is). It'll be a lot of work to realign data and you don't want to do that twice! In the meantime until you can get some GPS traces uploaded I'd just live with the offset and add features logically with respect to other features. Then, when you have enough local GPS traces to be sure about how much the data is offset you can begin the task of lining the data up.

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answered 01 Apr, 13:54

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SomeoneElse ♦
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edited 20 May, 15:40

I think you need to find the changeset that messed everything up. If you know a changeset you could start a discussion on it. That will help move things forward. I am not an expert either, I tried to look back through history, could this one be to blame:

Changeset: 65964144 Smoothed and aligned roads and driveways. #Kaart 2019 Closed 3 months ago by TigerTamer

i dont know how to see diffs of before and after.

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answered 31 Mar, 03:17

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OpenMapsRH
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You can see diffs on achavi, if the changeset is small enough. OSMCha also does this (although it seems to be struggling right now).

(01 Apr, 00:38) InsertUser

An example node from that changeset is https://www.openstreetmap.org/node/5287342639/history . That moved a node that's part of a road, but not any of the underlying buildings. Arguably this makes the eventual fixing job harder rather than easier as it means the the data offset isn't consistent (though it'd be unfair to say "messed everything up" the the data was wrong to start with). At the very least I'd suggest commenting on that changeset to make that user aware of this help discussion.

(01 Apr, 13:59) SomeoneElse ♦
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question asked: 30 Mar, 21:34

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