Add notes about CRS

w3c · May 2, 2019 · 3aad61a · 3aad61a
1 parent 4af68d5
commit 3aad61a
Showing 1 changed file with 28 additions and 4 deletions.
diff --git a/dcat/index.html b/dcat/index.html
@@ -2735,10 +2735,14 @@ <h4>Property: geometry</h4>
               <tbody>
               <tr><td class="prop">Definition:</td><td>Associates any resource with the corresponding geometry. [[LOCN]]</td></tr>
               <tr><td class="prop">Range:</td><td><a data-cite="RDF-SCHEMA#ch_literal" title="http://www.w3.org/2000/01/rdf-schema#Literal"><code>rdfs:Literal</code></a></td></tr>
-              <tr><td class="prop">Usage note:</td><td>The range of this property is intentionally generic, with the purpose of allowing different geometry encodings. E.g., the geometry could be encoded with as <abbr title="Well-known Text">WKT</abbr> (<a href="http://www.opengis.net/ont/geosparql#asWKT" title="http://www.opengis.net/ont/geosparql#asWKT"><code>geosparql:asWKT</code></a> [[GeoSPARQL]]) or [[GML]] (<a href="http://www.opengis.net/ont/geosparql#asGML" title="http://www.opengis.net/ont/geosparql#asGML"><code>geosparql:asGML</code></a> [[GeoSPARQL]]).</td></tr>
+              <tr><td class="prop">Usage note:</td><td>The range of this property is intentionally generic, with the purpose of allowing different geometry encodings. E.g., the geometry could be encoded with as <abbr title="Well-known Text">WKT</abbr> (<a href="http://www.opengis.net/ont/geosparql#asWKT" title="http://www.opengis.net/ont/geosparql#asWKT"><code>geosparql:asWKT</code></a> [[GeoSPARQL]]).</td></tr>
               </tbody>
             </table>
 
+            <p>
+              The WKT encoding supports geospatial positions expressed in coordinate reference systems other than WGS84.
+            </p>
+
             <p class="note">
               Property added in this revision of DCAT.
             </p>
@@ -2751,10 +2755,14 @@ <h4>Property: centroid</h4>
               <tbody>
               <tr><td class="prop">Definition:</td><td>The geographic center (centroid) of a resource.</td></tr>
               <tr><td class="prop">Range:</td><td><a data-cite="RDF-SCHEMA#ch_literal" title="http://www.w3.org/2000/01/rdf-schema#Literal"><code>rdfs:Literal</code></a></td></tr>
-              <tr><td class="prop">Usage note:</td><td>The range of this property is intentionally generic, with the purpose of allowing different geometry encodings. E.g., the geometry could be encoded with as <abbr title="Well-known Text">WKT</abbr> (<a href="http://www.opengis.net/ont/geosparql#asWKT" title="http://www.opengis.net/ont/geosparql#asWKT"><code>geosparql:asWKT</code></a> [[GeoSPARQL]]) or [[GML]] (<a href="http://www.opengis.net/ont/geosparql#asGML" title="http://www.opengis.net/ont/geosparql#asGML"><code>geosparql:asGML</code></a> [[GeoSPARQL]]).</td></tr>
+              <tr><td class="prop">Usage note:</td><td>The range of this property is intentionally generic, with the purpose of allowing different geometry encodings. E.g., the geometry could be encoded with as <abbr title="Well-known Text">WKT</abbr> (<a href="http://www.opengis.net/ont/geosparql#asWKT" title="http://www.opengis.net/ont/geosparql#asWKT"><code>geosparql:asWKT</code></a> [[GeoSPARQL]]).</td></tr>
               </tbody>
             </table>
 
+            <p>
+              The WKT encoding supports geospatial positions expressed in coordinate reference systems other than WGS84.
+            </p>
+
             <p class="note">
               Property added in this revision of DCAT.
             </p>
@@ -2772,6 +2780,10 @@ <h4>Property: latitude</h4>
               </tbody>
             </table>
 
+            <p>
+              The coordinate reference system for <code>w3cgeo:lat</code> values is <a href="https://en.wikipedia.org/wiki/World_Geodetic_System#WGS84">WGS84</a>.
+            </p>
+
             <p class="note">
               Property added in this context in this revision of DCAT.
             </p>
@@ -2789,6 +2801,10 @@ <h4>Property: longitude</h4>
               </tbody>
             </table>
 
+            <p>
+              The coordinate reference system for <code>w3cgeo:long</code> values is <a href="https://en.wikipedia.org/wiki/World_Geodetic_System#WGS84">WGS84</a>.
+            </p>
+
             <p class="note">
               Property added in this context in this revision of DCAT.
             </p>
@@ -2801,11 +2817,15 @@ <h4>Property: altitude</h4>
               <tbody>
               <tr><td class="prop">Definition:</td><td>Altitude (elevation) of a characteristic point location of a resource.</td></tr>
               <tr><td class="prop">Range:</td><td><a data-cite="XMLSCHEMA11-2#decimal"><code>xsd:decimal</code></a></td></tr>
-              <tr><td class="prop">Usage note:</td><td>The coordinate reference system for latitude / longitude / altitude values is <a href="https://en.wikipedia.org/wiki/World_Geodetic_System#WGS84">WGS84</a> (horizontally) and <a href="https://en.wikipedia.org/wiki/Sea_level#Height_above_mean_sea_level">Mean Sea Level</a> (vertically). It is recommended to encode the value as a <code>xsd:decimal</code>. </td></tr>
+              <tr><td class="prop">Usage note:</td><td>It is recommended to encode the value as a <code>xsd:decimal</code>. </td></tr>
               <tr><td class="prop">Usage note:</td><td>Use of this property entails that value of the <code>dct:spatial</code> property is a member of the <code>w3cgeo:Point</code> class from [[W3C-BASIC-GEO]]. This could be taken to imply that <code>w3cgeo:Point</code> is a subclass of <code>dct:Location</code></td></tr>
               </tbody>
             </table>
 
+            <p>
+              The datum for <code>w3cgeo:alt</code> values is <a href="https://en.wikipedia.org/wiki/World_Geodetic_System#WGS84">WGS84</a>.
+            </p>
+
             <p class="note">
               Property added in this context in this revision of DCAT.
             </p>
@@ -2818,10 +2838,14 @@ <h4>Property: bounding box</h4>
               <tbody>
               <tr><td class="prop">Definition:</td><td>The geographic bounding box of a resource.</td></tr>
               <tr><td class="prop">Range:</td><td><a data-cite="RDF-SCHEMA#ch_literal" title="http://www.w3.org/2000/01/rdf-schema#Literal"><code>rdfs:Literal</code></a></td></tr>
-              <tr><td class="prop">Usage note:</td><td>The range of this property is intentionally generic, with the purpose of allowing different geometry encodings. E.g., the geometry could be encoded with as <abbr title="Well-known Text">WKT</abbr> (<a href="http://www.opengis.net/ont/geosparql#asWKT" title="http://www.opengis.net/ont/geosparql#asWKT"><code>geosparql:asWKT</code></a> [[GeoSPARQL]]) or [[GML]] (<a href="http://www.opengis.net/ont/geosparql#asGML" title="http://www.opengis.net/ont/geosparql#asGML"><code>geosparql:asGML</code></a> [[GeoSPARQL]]).</td></tr>
+              <tr><td class="prop">Usage note:</td><td>The range of this property is intentionally generic, with the purpose of allowing different geometry encodings. E.g., the geometry could be encoded with as <abbr title="Well-known Text">WKT</abbr> (<a href="http://www.opengis.net/ont/geosparql#asWKT" title="http://www.opengis.net/ont/geosparql#asWKT"><code>geosparql:asWKT</code></a> [[GeoSPARQL]]).</td></tr>
               </tbody>
             </table>
 
+            <p>
+              The WKT encoding supports geospatial positions expressed in coordinate reference systems other than WGS84.
+            </p>
+
             <p class="note">
               Property added in this revision of DCAT.
             </p>