SimpleFeature Ontology

The Service Model Translator (SMT), which will be finished in the next weeks, translates service metadata from different OGC Web Services into WSDL and LinkedData.

If you want to create LinkedData out of the requested service data, you need a ontology which describes the requested features. Such a simple feature model has already been developed. The following figure shows the Concept Map:

The figure above shows that every feature is an AbstractFeature which has a "subClassOf" relation to AbstractGML. Each feature owns several properties. One of them is its geometry with the appropriated coordinates. The coordinates will be encoded in Well-known text markup language which is specified by OGCs Simple Feature Access.

Finally a possible output could be the following RDF document notated in RDF/XML;

<?xml version="1.0"?>
<rdf:RDF xmlns:ex="http://geordf.appspot.com/api/feature#" xmlns:ft="http://geordf.appspot.com/api/featuretype#" xmlns:gml="http://example.org/onto#" xmlns:rdfs="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
	<ft:Geol50K rdf:about="http://geordf.appspot.com/api/feature#feature_1">
		<gml:hasProperty>
			<gml:AbstractGeometry rdf:about="http://geordf.appspot.com/api/feature#geometry">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">Point (10 10)</rdf:value>
			</gml:AbstractGeometry>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:area rdf:about="http://geordf.appspot.com/api/feature#area">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">46958890.627100000000000</rdf:value>
			</ft:area>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:perimeter rdf:about="http://geordf.appspot.com/api/feature#perimeter">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">49043.622895900000000</rdf:value>
			</ft:perimeter>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:geol8 rdf:about="http://geordf.appspot.com/api/feature#geol8">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">2</rdf:value>
			</ft:geol8>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:geol8_id rdf:about="http://geordf.appspot.com/api/feature#geol8_id">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">1590</rdf:value>
			</ft:geol8_id>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:code rdf:about="http://geordf.appspot.com/api/feature#code">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">109.000000000000000</rdf:value>
			</ft:code>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:centroid_y rdf:about="http://geordf.appspot.com/api/feature#centroid_y">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">1821473.780320000000000</rdf:value>
			</ft:centroid_y>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:centroid_x rdf:about="http://geordf.appspot.com/api/feature#centroid_x">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">662297.706163000000000</rdf:value>
			</ft:centroid_x>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:description rdf:about="http://geordf.appspot.com/api/feature#description">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">Calcaires à Polypiers</rdf:value>
			</ft:description>
		</gml:hasProperty>
		<gml:hasProperty>
			<ft:formation rdf:about="http://geordf.appspot.com/api/feature#formation">
				<rdf:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#Literal">Plio-Pléistocène</rdf:value>
			</ft:formation>
		</gml:hasProperty>
	</ft:Geol50K>
</rdf:RDF>

or in a more human readable syntax like N3:

@prefix ft: <http://geordf.appspot.com/api/featuretype#>.
@prefix dc: <http://purl.org/dc/elements/1.1#>.
@prefix gml: <http://example.org/featureModel#>.
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
@prefix ex: <http://geordf.appspot.com/api/feature#>.
@prefix geom: <http://geordf.appspot.com/api/geometry#>.
@prefix xsd: <http:www.w3.org/schema/XMLSchmema#>.
@prefix rdfs: <http://www.w3.org/1999/02/22-rdf-syntax-ns-schema#>.


ex:feature_1 a ft:Geol50K;
	gml:hasProperty ex:geometry, ex:area,ex:perimeter,ex:geol8,ex:geol8_id,ex:code,ex:centroid_y,ex:centroid_x,ex:description,ex:formation.

ex:geometry a gml:AbstractGeometry;
	rdf:value "Point (10 10)"^^rdfs:Literal.
	
ex:area a ft:area;
	rdf:value "46958890.627100000000000"^^rdfs:Literal.
	
ex:perimeter a ft:perimeter;
	rdf:value "49043.622895900000000"^^rdfs:Literal.
	
ex:geol8 a ft:geol8;
	rdf:value "2"^^rdfs:Literal.
	
ex:geol8_id a ft:geol8_id;
	rdf:value "1590"^^rdfs:Literal.
	
ex:code a ft:code;
	rdf:value "109.000000000000000"^^rdfs:Literal.
	
ex:centroid_y a ft:centroid_y;
	rdf:value "1821473.780320000000000"^^rdfs:Literal.

ex:centroid_x a ft:centroid_x;
	rdf:value "662297.706163000000000"^^rdfs:Literal.
	
ex:description a ft:description;
	rdf:value "Calcaires à Polypiers"^^rdfs:Literal.
	
ex:formation a ft:formation;
	rdf:value "Plio-Pléistocène"^^rdfs:Literal.