Approaches to representing and delivering geospatial data in the semantic Web - Implications for EO data cubes. CSIRO Computational and Simulation Sciences and eResearch, Annual Conference

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Approaches to representing and delivering geospatial data in the semantic web:Implications for EO data cubes

Computational and Simulation Sciences and eResearch, Annual Conference 2015Melbourne 10-13 FebruaryPaul Box & Simon Cox

LAND & WATER FLAGSHIP | DIGITAL PRODUCTIVITY FLAGSHIP

Overview

• Towards a Digital Earth • Vector data and the emerging semantic web• Implications for EO data cubes

Geospatial data in the semantic web: impliactions for EO - CSS & eResearch, Melbourne 2015| Box2 |

Geospatial data in the semantic web: impliactions for EO - CSS & eResearch, Melbourne 2015| Box

Multi-disciplinary perspectives

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Source: - US National Science Foundation Critical Zone Observatory (CZO)

Rapidly discover, access, integrate, analyze, synthesize and present authoritative information


Towards Digital Earth

• Big data – 3Vs new sources - govt, industry, citizens NGO • Assimilation – extensive manual effort –time consuming GIS/RS environments

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Earth System Models

GEOSS

Policy/mngt. decision

Analysis/prediction

Other Data SourcesSocio-economic data

Earth Observation・ In Situ・ Airborne・ Space-based

Assimilation

Decision Support

Source Adapted from GEO SS10 year implementation planwww.apan.net/meetings/tokyo2006/presentation/JAXA2.ppt

Discover Access Understand Extract, Transform, Load

Use

Time and effort

Towards Digital Earth – data integration• Distributed constellations of systems • Complex information governance• Integrate, analyse and report using standardised geographies• Subjective constructs - features

• River• ASGS• Climate region • Catchment management unit

O&M Rasterpixel

Vectorgeom

Decision maker

- Observed properties- Features of interest

- grid cells/systems- coordinates

shape


Semantics?

Named features

Feature based approach• Identity (name, code) • Type• Coordinates/Geometry • Topology

Representing location - geospatial data


Concept

Relationship

• Identity - critical but currently ambiguous• Geometry – too much emphasis • Topology – conflated with geometry• Disconnection between

• spatial data • spatial and other data

What’s in a name?


‘Leichhardt’in Australia•Australian Gazetteer - 4 (52) - NSW, QLD•ASGS - 10 (12) NSW, VIC, QLD

in NSW•NSW Place Names - 3 (9)

Leichhardt (Sub) NSW

Feature typessuburb, parish, homestead

SA2, SA3, CED, IARE, state suburb (VIC, NSW & QLD)

county, parish, suburb

• One place - many names• Australia, Australie, أستراليا• Sydney, Syd, City of Sydney

• One name – many places

One spatial object - multiple identities

Geospatial information Other information resources

NSW Gaz (GNB NSW) 32679

Spatial Data Infrastructure (SDI)


Geonames http://sws.geonames.org/2160386/

ASGS (ABS) SSC11351

Nat Gaz (GA) NSW3267

Identity - ambiguous, unstable, poorly governed

Geometry and topology

• Unreliable, inefficient for representing topology – across data sets


LGA boundaries

Semantic web technologies to the rescue?• Creating the web of data• Descriptions of things + links between them

• Identify spatial objects using http URIs • link multiple geometry to statistics • organise/reference other data

• Link spatial objects • multiple identities for same object• different spatial objects based on topology


W3C

Geospatial information Statistical information (Implicitly geospatial)

GNB NSW 32679

Spatial Data Infrastructure (SDI)


Geonames 2160386

ABS ASGS SSC11351

GA Aus Gaz NSW3267

Linked spatial data to bridge existing gaps

Spatial IdentifierReference Framework

Index Crosswalk Use

How SIRF Works

SIRFSpatial

Information

StatisticalInformation User

Linked Data Web

Index identifiers

Agency BFinance

API

Agency C Welfare

API

Agency AStatistics

API

Publish URIs


Registering online resources to build data networks

(National) Spatial Data Infrastructure

http://demo.sirf.net/siset/CGNA/NSW81093

http://demo.sirf.net/siset/AUS-FSDF/admin/2owl:sameAs

http://demo.sirf.net/siset/CGNA/NSW81093

http://demo.sirf.net/siset/AUS-FSDF/admin/2

http://www.w3.org/TR/owl-ref/


SIRF data network 2

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SIRF indexes of vector spatial data (not cache) connected to source standardised linked vocabularies for spatial dimension of data cubes published into web of data

Spatial hierarchies and geo-federationin

dica

tor

Spatial (country) time

Australia

NSW

Spatial – (state)

Spatial (LGA)

Leichhardt


Other hierarchies: Biogeography, geofabric, …


Implications for EO data cube

• Similar concepts in EO - hierarchical nested grids e.g. ANZLIC National Nested Grid, OGC Discrete Global Grid• regular tessellation of the Earth • resolution and nesting regime • indexing system

• Analogous to vector world?• multiple grid systems in use• multiple identifiers for same location• mapping between them

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Implications for EO data cube

Scientists and decision-makers focus on named spatial objectsEO datasets are organized as indexed grids

• From regular grids to reporting geographies - pre-compute grid cells for reporting geographies

• Link between grid systems and vector data identifier schemes• User centric ways of accessing and using data• Publish as linked data

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Paul Box

t: +61 2 93253122e: [email protected]: www.csiro.au

DIGITAL PRODUCTIVITY FLAGSHIP

Thank youCSIRO Land and Water FlagshipDigital Productivity Flagship

SIRF OpenSearch UI http://unsdi.csiro.au/UNSDIOpenSearch/searchSIRF API doco http://www.sirf.net

Environment

Approaches to representing and delivering geospatial data in the semantic Web - Implications for EO data cubes. CSIRO Computational and Simulation Sciences and eResearch, Annual Conference