[OSM-talk] source=Google

[Christoph Hormann]

On Saturday 18 May 2013, Martin Koppenhoefer wrote:
> [...] Usually with aerial
> imagery from webmaps you also don't see from when they are, at least
> almost nobody stores this information in the source tag, but it is
> much more relevant (IMHO) to know "traced from aerial imagery from
> 2007" than "traced from bing aerials"

Much agreed, date of the images is much more relevant than the provider.  
The lack of this information in Bing etc. combined with the fact that 
first hand survey information is usually entered shortly after the 
survey has lead to a lack of practical need for entering this 
information.

> Your mention of geometry metadata reminds me of another point: a
> simple "source" is not enough, you'd need a distinct source tag for
> all properties not one source for the whole object.

I already had that in mind - i just explained it for the geometry only.  
Each tag could have its own metadata and this would be reset everytime 
the tag value is changed.

And of course in addition to 'source' one could think of various other 
metadata types.  The date is obvious but accuracy as well as 
reliability information could also be useful metadata.

-- 
Christoph Hormann
http://www.imagico.de/