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Sensor Metadata Management and its Application in Collaborative Environmental Research

Sensor Metadata Management and its Application in Collaborative Environmental Research. Nicholas Dawes, Ashwin Kumar, Sebastian Michel , Karl Aberer, Michael Lehning. Ecole Polytechnique Fédérale de Lausanne, Switzerland

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Sensor Metadata Management and its Application in Collaborative Environmental Research

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  1. Sensor Metadata Management and its Application in Collaborative Environmental Research Nicholas Dawes, Ashwin Kumar, Sebastian Michel, Karl Aberer, Michael Lehning Ecole Polytechnique Fédérale de Lausanne, Switzerland Swiss Federal Institute for Snow and Avalanche Research (SLF), Davos, Switzerland

  2. Outline • Introduction to Swiss Experiment (SwissEx) • Problem Statement and Motivation • The SwissEx Wiki • SwissEx Infrastructure (Data) • Semantic Forms • Querying Metadata • Conclusion and Future Work

  3. SwissExperiment Interdisciplinary Environmental Research • Swiss Experiment (SwissEx Aims): • Provision of a generic infrastructure of: • web based technologies • wireless communications • low cost high density sensors • to serve the environmental science community, encourage collaboration and provide a portal for public information on environmental research • Climate change forecasts show the greatest impact in high alpine scenarios. These changes are already being observed and answers to environmental questions need to be found quickly. The Swiss Experiment infrastructure aims to speed up that process • www.swiss-experiment.ch

  4. SwissEx Infrastructure • SwissEx infrastucture is built to serve many environmental research projects Black boxes indicate widespread research areas with multiple experiments within • Where experimental areas overlap, projects can work more efficiently by sharing data • Projects can benefit from external data sources

  5. Requirement for Metadata • Temperatures from Wannengrat, Davos 22/01/07 – 28/01/07 Seem legitimate for 2400m altitude in winter?

  6. Requirement for Metadata • Temperature/Humidity sensor 25/01/07 Sensor opening covered in reim The data from this sensor during the preceding period is unusable, but indistinguishable from the data after this photo was taken. …….never trust somebody elses data without the associated metadata

  7. The SwissEx WikiInformation, Data Portal and Metadata Database Interface • Central to the functioning of the project • Incorporates SensorMap and GSN access: • If you can access the data, this is the place to have the metadata access • MediaWiki uses RDF format to store semantics • RDF enables structure to be added to a mass of web based data

  8. SwissEx Infrastructure

  9. SwissEx Metadata

  10. The Metadata Model • The metadata model: Observation with station no. Invalid data registration Observation • Can also be viewed as: Observation with station no. Parameter Observation Invalid data registration

  11. Semantic Annotations

  12. Semantic FormsMetadata Database Interface • We can use semantic wiki language to store data in the background as RDF • Semantic wiki language is complicated, not what scientists need to deal with when they come back from the field • Semantic Forms take away this complexity at the expense of flexibility - a well designed system can simplify data entry

  13. Use of forms in entering semantics

  14. Station (Model Entity A) Observations pertianing to the overall station General info on the station/vs List of assigned sensors Addition of observations to the data or station/vs and notation of invalid data periods Parameters All possible sensor models

  15. Action (Model Entity B) Observation or invalid data between 2 dates

  16. Sensor (Model Entity C) Association between parameter name and model Associated parameter names

  17. Sensor Model (Model Entity D) Model information Association sensor instances (serial numbers)

  18. Parameter (Virtual Sensor) (Model Entity E) Parameter information Registered invalid data periods and observations Dependencies

  19. How do we make the tables? Semantic Queries Query languages for RDF databases: • Standard Wiki query {{#ask:[[station name::{{{stationname}}}]] [[Sensor serialno::+]]|?Sensor serialno|?Action|?Action at|format=table}} PREFIX a: <http://www.swiss-experiment.ch/index.php/Special:URIResolver/> SELECT DISTINCT ?smodel WHERE {?page a:Property:Sensor_model?smodel} • SPARQL query

  20. Semantic Queries PREFIX a: <http://www.experiment1.ch/index.php/Special:URIResolver/> PREFIX b: <http://www.experiment2.ch/index.php/Special:URIResolver/> SELECT ?smodel FROM NAMED <wiki1.rdf> FROM NAMED <wiki2.rdf> WHERE { GRAPH <wiki1.rdf> { ?x a:Property:Sensor_model ?smodel . } . GRAPH <wiki2.rdf> { ?y b:Property:Sensor_model ?smodel . } . } • BUT…. SPARQL can query multiple sources • So metadata from A,B,C,D and E can be queried simultaneously • SPARQL also gives us the possibility to query across metadata from different experiments……so we have the possibility of querying the data based on its metadata

  21. Metadata Export using SPARQL SPARQL is already used to query the wiki and import metadata to SensorMap

  22. Can I use the wiki as a front end for any database? • Importing to the Wiki from a relational database: • Using R2D2 (http://aksw.org) SPARQL queries can be translated to SQL for querying a relational database. The result is translated back to RDF format using the same tool. • The RDF files can be imported to a wiki page. • Why is this interesting? • If there are external data sources with metadata, we can query it and give the results in the same place as the rest of the data • Exporting to a relational database from the wiki: • A script should be written to perform the relevant SPARQL query and wrap the result into a SQL query.

  23. Conclusion • Framework for Metadata capturing • Integrated in a Wiki • Intuitive to use • Provide query interface to applications • Support for import/export to relational DBs

  24. Swiss Experiment Questions Interdisciplinary Environmental Research

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