Download - Meaningful URIs for Linked Sensor Data

Towards Meaningful URIs

for Linked Sensor Data

K. Janowicz, A. Broering, C. Stasch, T. Everding

Towards Digital Earth Workshop @ FIS2010, Berlin

September 20th, 2010

Vision

World Wide Web is for websites

HTTP

HTML

...

Sensor Web is for sensors

O&M

SOS

SPS

...

Arne Broering - [email protected]

Sensor Web Enablement (SWE)

http://www.ogcnetwork.net/swe

Web Service interfaces & data encodings

Building blocks for a Sensor Web


OGC®

SWE Functionality

Project: GITEWS

Sensor Observation Service

SensorML

O&M

GetCapabilities

DescribeSensor

GetObservation

GML GetFeatureOfInterest


Observations & Measurements

Feature of Interest:= „SeminarisHotelBerlin“

Sensor := „Weatherstation_Dahlem“

23 m/s 16.9.2010 13:45

Result

Unit of Measure

Sampling TimeObserved Property:= „Windspeed“


Observation

Observations & Measurements

class O&M

Observ ation

- samplingTime: Time

Procedure PropertyType «FeatureType»

AnyFeature

Any

+procedure

1

+observedProperty

1

+propertyValueProvider

0..*

+featureOfInterest

1

+result

1


Goal: Linked Sensor Data

To improve browsing & discovery of sensor data


Vision

World Wide Web is for websites / documents

HTTP

HTML

...

Sensor Web is for sensors

SOS

O&M

...

Linked Data Web is for linked data

RDF

...


Linked Data

Shift from linked documents to linked data

Establish links:

Documents: HTML

Data: RDF

Already available linked data:

people, companies, publications, books, movies, music, television

programs, genes, proteins…


Linked Data

Example usage:

What proteins are involved in signal transduction AND are

related to pyramidal neurons?

Google search: 200.000 hits, NO results

Linked Data search: 32 hits, 32 results

(see TED Talk from Berners-Lee)

Example “GEO”-usage:

Which sensors are located along the river Rhine AND

measure water level higher than 4,50 m during yesterday?


Linked Sensor Data

Requirements

Linked Data Model (in RDF)

Links between data chunks

Unified Resource Identifier (URI) Scheme


RESTful SOS Proxy for Linked Sensor Data


URI Scheme for Linked Sensor Data

Access to features of interest:

http://my.authority.org/foi

Example:

http://my.authority.org/foi/SeminarisHotelBerlin

Access to sensors:

http://my.authority.org/sensors

Example:

http://my.authority.org/sensors/Weatherstation_Dahlem



Access to observations:

http://my.authority.org/observations

Thematic filter:

../observation/<sensor>/<foi>/<observed property>

Example:

../observations/Weatherstation_Dahlem/SeminarisBerlin/windSpeed

Example “Wildcard”:

../observations/-/-/windSpeed



Temporal filter (aligned with ISO8601):

../observation/sensor/foi/observed property/<start date>/<end date>

<start date>:= <year>/<month>/<day>/<hour>/<minute>/<second>

<end date> := <year>/<month>/<day>/<hour>/<minute>/<second>

Example:

February 2010 - 1st July 2010 at 13:05:

../2010/02/-/-/-/-/2010/07/01/13/05/-/..



Spatial filter:

../<start>/<end>/<minLat>_<minLong>_<maxLat>_<maxLong>_<crs>

Example:

../52.12_7.45_52.34_7.56_urn:ogc:def:crs:EPSG::4326


RESTful SOS Architecture


Outlook

Linked Data model (O&M RDF)

Accepted by W3C Semantic Sensor Network Incubator Group

(http://www.w3.org/2005/Incubator/ssn/)

Meaningful Links within model

Include other SWE standards:

SensorML RDF

RESTful SES Proxy


Demo: RESTful SOS Proxy

http://v-swe.uni-muenster.de:8080/52n-OXF-WS/RESTful/sos

















Questions?

Thank you!

Arne Broering

[email protected]

52°North RESTful SOS Proxy: http://52north.org/RESTFul_SOS

52°North Semantics Community: http://52north.org/semantics

IfGI SWSL: http://swsl.uni-muenster.de

IfGI MUSIL: http://musil.uni-muenster.de