Using a Simple Knowledge Organization System to facilitate

Using a Simple Knowledge Organization System to facilitate Catalogue and Search for the ESA CCI Open Data Portal EGU, 21 April 2016 Antony Wilson, Victoria Bennett, Steve Donegan, Martin Juckes, Philip Kershaw, Ruth Petrie, Ag Stephens, and Alison Waterfall

Overview • ESA CCI and the open data portal • Challenge – different data sources – provide a range of search and data services • Solution – Use of linked data and SKOS

ESA Climate Change Initiative • Earth observation data • 13 essential climate variables (ECVs) • Multiple sources • Different scientific communities • Heterogeneous data

The Challenge Produce an Open Data Portal Establish a central repository to bring together the data from multiple sources and make them available in a consistent way, in order to maximize their dissemination amongst the international user community

Data Reference Syntax • A data reference syntax (DRS) was developed by the Earth System Grid Federation (ESGF) to support CMIP 5 – Storage and discovery of model data • Concept of DRS reused for CCI, but focussing on observation data • Defines a number of grouping / facets common to all observations data type platform institute essential climate variable (ecv) processing level sensor product time frequency • The CCI DRS was agreed and published in a standards document http: //cci. esa. int/sites/default/files/CCI_Data_Requirements_Iss 1. 2_Mar 2015. pd f

data scientist adds metadata output data standards document searching cataloguing

Cataloguing • Data are archived at the Centre for Environmental Data Analysis (CEDA) – CEDA are responsible for the cataloguing of the data • Data from 13 different providers • Metadata encoded in: – The file name • 2 different formats – Attributes of Net. CDF files

Vocabulary Server data scientist adds metadata output data human interface vocabulary server standards document machine interface validation cataloguing searching

Vocabulary Server • Single point of authority of the DRS • The use of SKOS to represent the DRS is well suited to deal with its complexity and variety • SKOS provides: – a means to represent controlled vocabularies – a way to represent relationships between similar terms used in different ECVs – a way to easily represent hierarchies and navigation up and down hierarchies of terms • Data is stored in a triple store with a SPARQL endpoint

SKOS http: //vocab-test. ceda. ac. uk/collection/cci/sensor a skos: Collection ; skos: pref. Label "Sensor"@en ; dc: title "Sensor" ; dc: description "The sensors that have been used in the collection of the data for the ESA Climate Change Initiative (CCI). " ; dc: creator "Science and Technology Facilities Council" ; dc: date "2016 -03 -22" ; dc: publisher "STFC"@en ; rdfs: comment "This collection represents the sensors used by the CCI project" ; skos: member <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_aatsr>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_ace>, <http: //vocab--test. ceda. ac. uk/collection/cci/sensor/sens_meris> <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_meris> a skos: Concept ; skos: pref. Label "MERIS"@en ; skos: definition "Medium-Spectral Resolution, Imaging Spectrometer"@en ; cci: has. Platform <http: //vocab-test. ceda. ac. uk/collection/cci/platform/plat_envisat>.

CCI Open Data Portal search data files under development data scientist adds metadata ESGF Publisher human interface vocabulary server machine interface search datasets OGC CSW machine interface output data machine interface searching ISO 19115 records validation MOLES cataloguing (ISO 19156)

http: //vocab-test. ceda. ac. uk/collection/cci/sensor a skos: Collection ; skos: member <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_aatsr>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_ace. Fts>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_airs>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_ami. Ws>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_amsr 2>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_amsre>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_amsu>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_asar>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_ascat>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_aster>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_atsr>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_avhrr. Gac>, <http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_avhrr. Hrpt>,

<http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_meris> a skos: Concept ; skos: pref. Label "MERIS"@en ; skos: definition "Medium-Spectral Resolution, Imaging Spectrometer"@en ; cci: has. Platform <http: //vocab-test. ceda. ac. uk/collection/cci/platform/plat_envisat>.

<csw: Get. Records xmlns: csw="http: //www. opengis. net/cat/csw/2. 0. 2" service="CSW" version="2. 0. 2" result. Type="results" output. Schema="http: //www. isotc 211. org/2005/gmd"> <csw: Query type. Names="csw: Record"> <csw: Element. Name>/gmd: MD_Metadata</csw: Element. Name> <csw: Constraint version="1. 1. 0"> <Filter xmlns="http: //www. opengis. net/ogc" xmlns: gml="http: //www. opengis. net/gml"> <And> <Property. Is. Equal. To> <Property. Name>keyword. Uri</Property. Name> <Literal>http: //vocab-test. ceda. ac. uk/collection/cci/sensor/sens_meris</Literal> </Property. Is. Equal. To> </And> </Filter> </csw: Constraint> </csw: Query> </csw: Get. Records>' http: //csw 1. cems. rl. ac. uk/geonetwork-CEDA/srv/eng/csw-CEDA-CCI

Conclusions • Vocabulary server enables central management of – Controlled vocabularies – Definitions of terms – Relationships between term, internally and externally • Assists in integrating multiple services, providing richer content • Reuse by CLIPC project – Make use of NERC vocabulary server

Acknowledgements • • • Telespazio VEGA UK University of Reading CGI Centre for Environmental Data Analysis Scientific Computing, RAL • This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 607418