Re: How to represent geographic coordinates for maps

Hi Lars,

To question 3: First, I think that depending on the projection and
scale, a rectangle on a map is not/only nearly representable by a
rectangle in geocoordinates.
Furthermore, the representation you chose (""W 13' - E 49' / N 45°58' -
N 45°33'""") is not very easily machine-readable because you code a
rectangle into a single literal and also use a coordinate notation that
needs additional parsing.
Maybe polygons like the ones used in LinkedGeoData would be helpful? A

Regards,
Konrad

On 12.07.2013 11:14, Svensson, Lars wrote:
> All,
>
> At the German National Library we are currently looking into how to represent coordinates for maps and we need some advice on which representation would be most useful for the community.
>  
> While looking at publishing coordinates for places in the library authority data, we also started looking at how to represent the geographic extent of maps. I came across three vocabularies that could be useful for that:
> 1) the (library-specific?) properties scale: http://rdvocab.info/Elements/scale, projection: http://rdvocab.info/Elements/projectionOfCartographicContent and coordinates: http://rdvocab.info/Elements/coordinatesOfCartographicContent from RDA (Resource Description and Access)
> 2) the properties from wgs84_pos
> 3) the properties from geosparql
>  
> If I have understood things correctly, only the RDA ones are applicable directly for a map, whereas wgs84 and geosparql really are about places and not about maps, so that you would need to introduce a level of indirection to use them directly for maps. A (made-up) example:
>
> my:resource a ex:Map ;
>         dc:title "The Marauder's Map" ;
>         rdvocab:coordinatesOfCartographicContent """W 13' - E 49' / N 45°58' - N 45°33'""" .
>
> my:resource a ex:Map ;
>         dc:title "The Marauder's Map" ;
>         dct:coverage [ a wgs84_pos:SpatialThing ;
>                 wgs84_pos:lat_long """ W 13' - E 49' / N 45°58' - N 45°33'""" ;
>                 .
>         ] .
>  
> So my three questions:
> 1) Is my interpretation of the use of wgs84 for maps correct?
> 2) Are coordinates for maps of any use at all to this community?
> 3) (If the answer to 2) is yes): which representation would be the best for your use cases?
>
> Thanks in advance for any insight,
>
> Lars
>
> ***Lesen. Hören. Wissen. Deutsche Nationalbibliothek***
> ***Reading. Listening. Understanding. German National Library***
>

Received on Friday, 12 July 2013 12:29:40 UTC