- From: Phil Archer <phila@w3.org>
- Date: Wed, 4 Jan 2017 17:27:03 +0000
- To: Philippe Le Hegaret <plh@w3.org>, Chairs <chairs@w3.org>
- Cc: SDW WG Public List <public-sdw-wg@w3.org>
Philippe, The Spatial Data on the Web WG would like to publish two (related) FPWD Notes (along with a couple of updated docs) tomorrow. These are part of the WG's work to address the charter deliverable 'Coverages in Linked Data' although the WG does not intend for these to become Recs as envisaged by the charter. Both should go under the Data on the Web category under TR space (also relevant to Geospatial of course). Doc title: Publishing and Using Earth Observation Data with the RDF Data Cube and the Discrete Global Grid System URL: https://www.w3.org/TR/2017/NOTE-eo-qb-20170105/ Requested short URL: https://www.w3.org/TR/eo-qb/ Working Group decision: https://www.w3.org/2016/12/15-sdw-minutes#eoqb (status section was updated as the resolution requires). Abstract: This document describes how dense geospatial raster data can be represented using the W3C RDF Data Cube (QB) ontology [vocab-data-cube] in concert with other popular ontologies including the W3C/OGC Semantic Sensor Network ontology (SSN) [vocab-ssn], the W3C/OGC Time ontology (Time) [owl-time], the W3C Simple Knowledge Organisation System (SKOS) [skos-reference], W3C PROV-O [prov-o] and the W3C/OGC QB4ST [vocab-qb4st]. It offers general methods supported by worked examples that focus on Earth observation imagery. Current triple stores, as the default database architecture for RDF, are not suitable for storing voluminous data like imagery derived from Landsat satellite sensors. We show how SPARQL queries can be served through an OGC Discrete Global Grid System for observations, coupled with a triple store for observational metadata. While the approach may also be suitable for other forms of coverage data, we leave the application to such data as an exercise for the reader. ------------ Document title: QB4ST: RDF Data Cube extensions for spatio-temporal components URL: https://www.w3.org/TR/2017/NOTE-qb4st-20170105/ Requested Short URL: https://www.w3.org/TR/qb4st/ Working Group decision: https://www.w3.org/2016/12/15-sdw-minutes#qb4st (HTML errors have been fixed as noted in the resolution). Abstract: This document describes an extension to the existing RDF Data Cube ontology to support specification of key metadata required to interpret spatio-temporal data. The RDF Data Cube defines CodedProperties, which relate to a reference system based on a list of terms, QB4ST provides generalized support for numeric and other ordered references systems, particulary Spatial Reference Systems and Temporal Reference Systems. Although RDF Data Cube supports AttributeProperties for metadata of individual observations, the requirement is to specify such metadata per property, rather than for the entire observation, and thus allow different properties to use different spatial or temporal reference systems. QB4ST also provides for such properties to be defined for a ComponentProperty, or defined at the time of referencing that ComponentProperty in a ComponentSpecification. QB4ST is thus aimed at improving the scope and consistency of dataset metadata, and hence discovery and interpretation of spatio-temporal data through its spatio-temporal reference system and bounding values. -- Phil Archer Data Strategist, W3C http://www.w3.org/ http://philarcher.org +44 (0)7887 767755 @philarcher1
Received on Wednesday, 4 January 2017 17:27:18 UTC