Open danrademacher opened 3 years ago
i will use multiple sources where necessary. this can come up for example when trying to nail down start_date and end_date. there are other situations.
For multiple maps on a single element, let's just do map:1
and name:1
, map:2
, name:2
...
Not sure if I follow how that might work if we needed additional info... e.g. map:1=url to map source map:1:date=date of map map:1:name=name, if one map:1:warped=link to warped map (diff from 1???)
@jeffreyameyer it would be super helpful to get a couple of specific examples of actual georectified, tiled maps that we imagine as the source for this feature, so that would help us then see what fields we need at a minimum for the thing to work at all, and what are nice to have.
Sure! (apologies, as we're sort of prototyping in real time here...
Check out: https://www.openhistoricalmap.org/way/198291609 - set the time slider to 1856 & most of those elements should match the tags below.
I'll try to clean up another area to match, probably London.
I'll take your thoughts, @danrademacher & put some more thoughts on 'em!
Challenges
I think this will happen a lot, as this is where the old triple-sourcing will come in handy. I think we should be encouraging people to limit this to the oldest sources possible and to just 3. Now, 3 sources for every building in a city could yield... a lot of maps. Would that be a bad thing? London's Regent Park zoo should provide a nice use case.
That's indeed what I'm encountering. I'm wondering what the answer for this might be without creating some sort of onerous infrastructure? The good news is that JOSM offers some auto-fill help on this front. (which can replicate errors quickly!)
Yes, but I think that's ok... AND... this very issue (universal indexing of old maps somehow)... might be solved somewhere else. Or, we could have a recommended priority of sourcing based on likelihood of a source being around (e.g. universities, LoC, etc.)
Following up on 2) from above - how to avoid tagging every item on a way with source info:
a) As it may be helpful to source just a few items from a map, it seems there might be no way around requiring support for individual map tagging on individual ways.
b) That said, I thought about using relations to identify all of the items from a map. Problem with that is that relations have many restrictions on them that will generate a lot of errors for users (I ignore these, but it's a little at your own peril; see: https://wiki.openstreetmap.org/wiki/Talk:Relation:multipolygon#Touching_inner_rings).
@rwelty1889 @geohacker @batpad - any thoughts here?
In a recent conversation with @jeffreyameyer, we discussed developing a new widget that would highlight historic maps used to map elements in the viewport and then allow users to add those historic maps as overlays on the main OHM map.
This is an initial overview issue to list out assumptions and approaches.
Assumptions
Note that for 3 we might want to match the capabilities for WMS and TMS links in iD:
Challenges
Design and Development
We could proceed with implementing this feature in the following way:
@jeffreyameyer can you review and comment on this issue for accuracy to what you're imagining? And check our assumptions!