[openstreetmap/openstreetmap-website] add optional coordinate epoch to nodes (#3203)
Andrew Harvey
notifications at github.com
Mon May 24 13:26:10 UTC 2021
The diary at https://www.openstreetmap.org/user/StephaneP/diary/390290 has some good detail.
> Surely the general errors and inconsistencies in imagery alignment far exceed any variation related to plate movement?
In ACT, AU, the government publish aerial imagery mappers use to trace in editors. Sampling a random area it's within about 0.6m. When they changed datum the imagery is published in from 1994 to 2020 the imagery noticeably shifted 1.8m. So someone tracing features against the imagery with the old datum, now has to manually move all their nodes 1.8m to align with the new imagery.
Traditionally the OSM way would be to offset the new imagery in the editor to align with the old, but it's workaround more suited when you have poor referencing in the imagery, and even then without a coordinate epoch attribute on the node, we don't actually know where all the imagery is aligned to.
In ACT we know exactly which epoch the imagery is aligned.
--
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/openstreetmap/openstreetmap-website/issues/3203#issuecomment-847041268
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/rails-dev/attachments/20210524/26e56699/attachment.htm>
More information about the rails-dev
mailing list