For example CC BY-SA forces to use the same license in any derivative work. And CC BY-NC allows noncommercial purposes. However, ODbL allows commercial purposes and it is different license from CC BY-SA.
Therefore, an orthophoto licensed with any of the 2 previous licenses are not allowed to map in OSM.
In contrast, the license CC-BY allows the use in OSM, only if there is a waiver note (attribution in reasonable manner and parallel distribution when DRM). Then, if an orthophoto under CC BY license could be used to map in OSM, only if it has the waiver note.
The issue is that OpenAerialMap is a well-know tool to upload images to use to map in OSM, and it allows to choose from 2 incompatible licenses, and 1 license without a space to put the waiver note:
I think OpenAerialMap should not allow the uploading of CC BY-NC or CC BY-SA images, because they are incompatible with OSM. Also, it should provide a space for the waiver note when using CC BY. And finally provide another options, like CC0 which are 100% compatible with ODbL.
Insert the usual proviso about grey areas here, but it isn’t necessarily the case that any copyright asserted in an aerial image restricts tracing from that image. I wrote about this a very long time ago: Système D » Aerial photography, cock fighting and vodka bottles
At the time the LWG made clear that tracing from aerial imagery shouldn’t create a derivative and likely would be considered transformational fair use even if it did, but it is simply better to take the high ground and make sure that the producer of the imagery is aware of what OSM is doing and what our legal take on this is.
Mandatory note, particularly when dealing with government data, there may be national and local laws and regulations outside of “copyright” law.
It would be great to get some clarification on this, because - as a user of OAM, but not for OSM purposes - the licensing terms are quite confusing. Whether or not the images can be used in OSM under an exception (there is an additional statement not in Andres’s screenshot that says tracing is an explicit exception), currently there is a blanket statement on the website (and also in the documentation for OIN):
All imagery is publicly licensed and made available through the Humanitarian OpenStreetMap Team’s Open Imagery Network (OIN) Node. All imagery contained in OIN is licensed CC-BY 4.0, with attribution as contributors of Open Imagery Network. All imagery is available to be traced in OpenStreetMap.
So if someone downloads imagery from OAM and wishes to use it elsewhere, do they assume the CC-BY 4.0 license and attribute OIN, or does the underlying license apply? Lots of hosted imagery contains conflicting license information in the metadata:
If the latter, then it’s factually incorrect to say that all imagery in OIN is CC-BY 4.0 (or is OAM just ignoring OIN’s spec?) and it’s dangerously/legally misleading to end-users who might take imagery and redistribute it under a more permissive license than the content creator specified.
(Another issue is that CC BY-SA and CC BY-NC are fundamentally incompatible licenses, so any downstream use of OAM imagery would have to make sure that they don’t mix images in those categories).