[HOT] Date of a mapped feature?

Chris Braun brauncch at gmail.com
Sat May 2 13:21:25 UTC 2015


Hello,

Thanks for your answers. Based on the answers I got, I think we should 
distinguish between 3 different related issues:
- *ISSUE 1:* Get the date if the imagery provides the information 
(applies e.g. for Bing, not for Mapbox) --> Explain how to do this in 
iD, Potlatch, JOSM or without editor
- *ISSUE 2:* Get the date if the imagery does not provide the 
information (e.g. for MapBox) --> Ask the data provider to add this 
information
- *ISSUE 3:* In case the date of the imagery is provided, deal with the 
zoom level issue.

Further details/questions to each issue:

*ISSUE 1: **Get the date if the imagery provides the information*
I will try to summarise, based on the answers you sent to my post, how 
to find out, given a specific feature (for instance way 58754640) the 
date of the most recent imagery (in this case Bing) which was used to 
draw/validate this feature. Actually, this describes how to reach the 
changeset page for the feature, but from there I still don't know how to 
get the information I am looking for. Could you correct/complete this?

Notice that I don't use Potlatch, so I will limit this post to A) 
nothing, B) iD editor and C) JOSM.

_A) Nothing (directly in openstreetmap.org)_
1) In openstreetmap.org, go to the relevant location --> 
https://www.openstreetmap.org/#map=17/27.70641/85.29392
2) Click on "Layers" (right sidebar) then "Map data" --> each feature 
gets a blue line (for ways) or circle (for nodes) around it
3) Click on the relevant feature (here way 58754640) --> opens 
https://www.openstreetmap.org/way/58754640#map=17/27.70641/85.29446&layers=D
4) Click on "View history" (link at the bottom of the left sidebar) --> 
opens https://www.openstreetmap.org/way/58754640/history
I can see it was created 5 years ago and last updated 4 months ago. Then 
I click on the latest changeset (which I could have done directly in 
step 3) --> opens https://www.openstreetmap.org/changeset/28154865
In the tags I can read "created_by:    iD 1.6.2" and "imagery_used: Bing".
But how can I get the date of the Bing image which was used??

_B) Using iD editor _
1) Click on the feature
2) Click on "View on OpenStreetMap.org" in the bottom left --> opens 
https://www.openstreetmap.org/way/58754640
This brings me to the same step as A3 above. So the same question applies.

_C) Using JOSM_
1) Click on "Download", I select Bounding Box with e.g. (27.70/27.71 - 
85.29/85.30)
2) Click on the way I am interested in (way 58754640)
3) Click on View->History, which opens the window "History for way 58754640"
Again, I get the same information as in step A4 above.

So is it the right way to go and how to find the date of the imagery then?

*ISSUE 2: **Get the date if the imagery does not provide the information 
(e.g. for MapBox) *
Since MapBox does not provide the date information, would it be possible 
to ask MapBox to add this? What would be the way to go to do this request?

*ISSUE 3: **In case the date of the imagery is provided, deal with the 
zoom level issue *
To be honest, I did not really understand the problem here. What I am 
asking is the latest date of a single feature, not of an overall image 
or area. This is an information I would expect to find in the changeset 
of a feature or elsewhere with the data associated to a feature. Which 
is not dependent of the zoom level, right?

Thanks a lot for your help!
Chris

On 02/05/2015 13:29, Pat Tressel wrote:
> Nicholas and Andre --
>
> Chris is asking about the date of the *imagery* used for tracing, not 
> the date of the traced elements.
>
> All --
>
> He makes an excellent point.  If imagery is several years old, then 
> features being traced may well have changed, with the likelihood being 
> higher for more ephemeral human-made structures.  For this purpose, 
> would be nice if imagery sets had metadata that included a creation 
> date, but I'm looking at the TMS spec, and don't see it, or any field 
> that could be used for it:
> http://wiki.osgeo.org/wiki/Tile_Map_Service_Specification
>
> -- Pat

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