diff --git a/ontology/saref4envi.ttl b/ontology/saref4envi.ttl
index ac958b94e3d4c3d6d84cd60eba86c0d1794c14e1..7da0858739151771559a792d49559be79bf9e08e 100644
--- a/ontology/saref4envi.ttl
+++ b/ontology/saref4envi.ttl
@@ -1,5 +1,4 @@
 @prefix : <https://saref.etsi.org/saref4envi/> .
-@prefix geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> .
 @prefix owl: <http://www.w3.org/2002/07/owl#> .
 @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
 @prefix xml: <http://www.w3.org/XML/1998/namespace> .
@@ -10,6 +9,7 @@
 @prefix s4envi: <https://saref.etsi.org/saref4envi/> .
 @prefix saref: <https://saref.etsi.org/core/> .
 @prefix dcterms: <http://purl.org/dc/terms/> .
+@prefix geo: <http://www.opengis.net/ont/geosparql#>.
 @base <https://saref.etsi.org/saref4envi/> .
 
 <https://saref.etsi.org/saref4envi/> rdf:type owl:Ontology ;
@@ -168,13 +168,6 @@ vann:preferredNamespaceUri rdf:type owl:AnnotationProperty .
 #    Data properties
 #################################################################
 
-###  https://saref.etsi.org/saref4envi/hasCreationDate
-:hasCreationDate rdf:type owl:DatatypeProperty ,
-                          owl:FunctionalProperty ;
-                 rdfs:range xsd:dateTime ;
-                 rdfs:comment "A relationship defining the creation date of an entity (e.g., a digital representation)."@en ;
-                 rdfs:label "has creation date"@en .
-
 
 ###  https://saref.etsi.org/saref4envi/hasFlash
 :hasFlash rdf:type owl:DatatypeProperty ,
@@ -260,44 +253,6 @@ vann:preferredNamespaceUri rdf:type owl:AnnotationProperty .
                   rdfs:label "Compass direction"@en .
 
 
-###  https://saref.etsi.org/saref4envi/Device
-:Device rdf:type owl:Class ;
-        rdfs:subClassOf saref:Device ,
-                        :System ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :hasFrequencyMeasurement ;
-                          owl:allValuesFrom :FrequencyMeasurement
-                        ] ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :hasTransmissionPeriod ;
-                          owl:allValuesFrom :PeriodMeasurement
-                        ] ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty saref:hasManufacturer ;
-                          owl:allValuesFrom xsd:string
-                        ] ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :hasRevisionNumber ;
-                          owl:allValuesFrom xsd:string
-                        ] ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :hasVersion ;
-                          owl:allValuesFrom xsd:string
-                        ] ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :hasRevisionNumber ;
-                          owl:maxQualifiedCardinality "1"^^xsd:nonNegativeInteger ;
-                          owl:onDataRange xsd:string
-                        ] ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :hasVersion ;
-                          owl:maxQualifiedCardinality "1"^^xsd:nonNegativeInteger ;
-                          owl:onDataRange xsd:string
-                        ] ;
-        rdfs:comment "A thing made or adapted for a particular purpose, especially a piece of mechanical or electronic equipment. For example ‘a measuring device’ (definition taken from https://en.oxforddictionaries.com/definition/device). In this ontology it refers to the devices for environmental purposes."@en ;
-        rdfs:label "Device"@en .
-
-
 ###  https://saref.etsi.org/saref4envi/DigitalRepresentation
 :DigitalRepresentation rdf:type owl:Class ;
                        rdfs:subClassOf [ rdf:type owl:Restriction ;
@@ -440,11 +395,7 @@ vann:preferredNamespaceUri rdf:type owl:AnnotationProperty .
 
 ###  https://saref.etsi.org/saref4envi/LightPoint
 :LightPoint rdf:type owl:Class ;
-            rdfs:subClassOf geo:Point ,
-                            [ rdf:type owl:Restriction ;
-                              owl:onProperty geo:location ;
-                              owl:allValuesFrom geo:SpatialThing
-                            ] ,
+            rdfs:subClassOf saref:FeatureOfInterest , geo:Feature ,
                             [ rdf:type owl:Restriction ;
                               owl:onProperty :projectsLight ;
                               owl:allValuesFrom :Light
@@ -487,21 +438,6 @@ vann:preferredNamespaceUri rdf:type owl:AnnotationProperty .
             rdfs:label "Photometer"@en .
 
 
-###  https://saref.etsi.org/saref4envi/System
-:System rdf:type owl:Class ;
-        rdfs:subClassOf saref:FeatureOfInterest , geo:Feature ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :usesCommunicationInterface ;
-                          owl:allValuesFrom :CommunicationInterface
-                        ] ,
-                        [ rdf:type owl:Restriction ;
-                          owl:onProperty :usesCommunicationProtocol ;
-                          owl:allValuesFrom :CommunicationProtocol
-                        ] ;
-        rdfs:comment "A group of related hardware units or programs or both, especially when dedicated to a single application. (Definition taken from https://en.oxforddictionaries.com/definition/system)"@en ;
-        rdfs:label "System"@en .
-
-
 ###  https://saref.etsi.org/saref4envi/TESS
 :TESS rdf:type owl:Class ;
       rdfs:subClassOf :Photometer ;