Use W3C PROV XML

46 Copyright © 2014 Open Geospatial Consortium.

10.2 Alternative storage methods

This Subsection will expose 2 different strategies to store provenance information explored in OWS10.

10.2.1 Storing provenance in an independed catalogue

Normally, ISO 19115 metadata documents are stored in CSW catalogues. In particular, catalogues conformal to OGC Catalogue Services Specification 2.0.2 - ISO Metadata Application Profile 1.0.0 are able to return the XML encoded documents. XML encodings for W3C PROV can be stored in an ebRIM catalogue if this is adapted to support the W3C PROV data model. Nobody was willing to try this approach and we were not able to assess the difficulty of doing this. 10.2.2 Storing provenance information embedded in GML 10.2.2.1 Storing ISO 19115 lineage information embedded in GML GML offers the possibility to embed an ISO document directly in a feature or a feature collection by defining a complex property type derived from AbstractMetadataPropertyType. complexType name=SpringISOMetadataPropertyType complexContent extension base=gml:AbstractMetadataPropertyType sequence element ref=gmd:MD_Metadata minOccurs=0 sequence attributeGroup ref=gml:AssociationAttributeGroup extension complexContent complexType and use it to create of property for a feature or a feature collection complexType name=SpringType complexContent extension base=gml:AbstractFeatureType sequence element name=metadata type=xmp:SpringISOMetadataPropertyType minOccurs=0 element name=name type=string minOccurs=0 maxOccurs=unbounded sequence extension complexContent complexType This way it is possible to embed a metadata document in a GML document: Copyright © 2014 Open Geospatial Consortium. 47 xmp:Spring xmp:metadata gmd:MD_Metadata... xmp:metadata xmp:nameSilver springxmp:name xmp:Spring The same trick can be used to embed just the provenance information or just a source or a process step: complexType name=SpringISOSourcePropertyType complexContent extension base=gml:AbstractMetadataPropertyType sequence element ref=gmd:LI_Source minOccurs=0 sequence attributeGroup ref=gml:AssociationAttributeGroup extension complexContent complexType So that allows them to enumerate sources and process steps: xmp:Spring gml:id=GoldSpring xmp:isoSource gmd:LI_Source... xmp:isoSource xmp:isoProcesStep gmd:LI_Process... xmp:isoProcesStep xmp:position... xmp:nameGold springxmp:name xmp:Spring Nevertheless this strategy can be very verbose, because it forces us to repeat the description of the process and source for each feature. Fortunately, there is xlink mechanism not just in GML also in the ISO19139 even if the later is rarely used. This mechanism allows referencing provenance descriptions in other document by using just an id avoiding unnecessary repetitions. xmp:Spring gml:id=ID_SPRING_1 xmp:isoSource xlink:href=https:bob.opengeospatial.orgSpringDatasetISOLineage.xml SC_USGS xmp:isoProcesStep xlink:href=https:bob.opengeospatial.orgSpringDatasetISOLineage.xml PS_WPS_1 xmp:position... xmp:nameGold springxmp:name xmp:Spring