Best Practice for encoding spatial coverage

Hello all,

Is it OK to try to venture in to the domain of best practices already? I
wonder if we can try our hands at the following issue:

I have just had a talk with a web developer on the best way of making the
extent of a spatial data set known, in a Linked Data context. It is useful
to know the spatial extent of a data set because that way a map can be
zoomed in on the right patch of Earth.

I think an obvious predicate for making the extent known is dcterms:spatial
<http://dublincore.org/documents/dcmi-terms/#terms-spatial> (Spatial
Coverage). That should point to a dcterms:Location
<http://dublincore.org/documents/2012/06/14/dcmi-terms/?v=terms#terms-Location>,
which can have a geometry. So an option would be to encode the extent as a
WKT polygon, according to GeoSPARQL semantics. But that would not be the
most webdeveloper-friendly way of making the extent known.  The usual way
of setting a map extent involves knowing the minimum and maximum values for
X and Y. So a question is: what would be the best way to publish the
minimum and maximum X and Y? There are usable vocabularies for publishing
point coordinates, so one could think of recommending to publish two points
(lower left corner and upper right corner). Perhaps there are standard
vocabularies available that define the concepts of 'minimum' and 'maximum'
and 'x' and 'y'?

I should note that this issue relates to the Spatial metadata requirement
<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialMetadata>
.


Greetings,
Frans



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Frans Knibbe
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