[Esip-documentation] Geospatial Bounds

[Aleksandar Jelenak via Esip-documentation]

On 10/7/14, 5:26 PM, “Bob Simons" <esip-documentation at lists.esipfed.org>
wrote:
>Also, in ISO 19115/19139, gmd:EX_GeographicBoundingBox is always
>specified with longitude and latitude (gmd:(east|west)BoundLongitude,
>gmd:(north|south)BoundLatitude) (never projection x, y values) and no CRS.

That seems to be correct but geospatial_bounds content is not for
specifying simple bounding boxes. That content is more appropriate as
EX_BoundingPolygon, which uses GML, which requires a CRS:
http://en.wikipedia.org/wiki/Geography_Markup_Language#Coordinate_Reference
_System

If we prescribe the (lon,lat) ordering but do not provide a CRS, what is
the default CRS to assume? WGS-84? If so, that one prescribes (lat, lon)
ordering so using directly the WKT string from geospatial_bounds attribute
will cause problems, no?

The reason why knowing/assuming a CRS matters is to support more advanced
operations with those geometric objects then simple value comparison
operations (greater/less than…) typically used for bounding boxes.

I am afraid we are dumbing down geospatial_bounds trying to make it look
too much like geospatial_lat_lon_min_max attributes. If bounding boxes
will work for your data, or your data discovery system — great, but let’s
not oversimplify something that is aimed for more sophisticated use.

	-Aleksandar