Xiaogang Ma; Peter A. Fox - Exploratory visualization of earth science data in a Semantic Web context - Presentation IN53D-07 at AGU Fall Meeting 2012

1. TWC
Exploratory visualization of earth science
data in a semantic web context
Xiaogang (Marshall) Ma, Peter Fox
Tetherless World Constellation
Rensselaer Polytechnic Institute
AGU Fall Meeting 2012, San Francisco,
Session IN53D. Semantics and Cyberinfrastructures for Next Generation Science II
12/07/2012

2. TWC
What is exploratory visualization
• “the process that involves a discipline
expert creating maps and other
graphics while dealing with relatively
unknown geographic data”
(Kraak, 2008)
• “Visualization too often becomes an
end product of scientific analysis,
rather than an exploration tool that
scientists can use throughout the
research life cycle.”
(Fox and Hendler, 2011)
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3. • (Big) Motivation
TWC
Motivation & Objective
– Online services of earth science data have been
increasingly built in recent years.
– Tools and services supporting information retrieval with
those data services are still underdeveloped.
…
• (Small) Objective
– A pilot study: Annotation, visualization, and filtration of
rock age (geologic time) information from online
geological map services
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4. TWC Idea
Experience
Data Information Knowledge
Creation Presentation Integration
Gathering Organization Conversation
Context 4

5. Geological
TWC Idea
Exploratory
map Ontology
services Visualization
Experience
Data Information Knowledge
Creation Presentation Integration
Gathering Organization Conversation
Context Semantic Web
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6. • Data source:
TWC Actions
reuse available services
• Annotation: build and reuse ontologies
• Visualization: a channel between rock age data
services and annotation and
filtration operations
• Filtration: a sample of exploratory
visualization
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7. TWC Data source
• Web Map Service (WMS) of British Geological
Survey
– WMS: a HTTP interface for requesting geo-registered
map images from distributed geospatial databases
(http://www.opengeospatial.org/standards/wms)
• WMS operations
– GetCapabilities (mandatory), GetMap (mandatory),
GetFeatureInfo (optional)
– SLD WMS only: DescribeLayer, GetLegendGraphic,
GetStyles, PutStyles, etc.
SLD: Styled Layer Descriptor - an XML schema 7

8. TWC
A sample of ‘GetFeatureInfo’
Output format:
• Text/xml
• Text/html
• Text/plain
…
1) Click a feature 2) Information returned
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9. TWC
Annotation: build and reuse
ontologies
• An ontology of geologic time scale (GTS)
– Ordinal hierarchical structure
A 7-level hierarchy
Ordinal arrangement of concepts at each level
– 175 concepts
e.g., Triassic, Middle Triassic, Induan, etc.
– Definition of concepts
Reuse existing works
– Encoding
SKOS, RDFS, OWL
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10. TWC
“Lower Triassic” in the hierarchy
RDF triples
Series Middle_Triassic
isA
gts:lowerThan Olenekian
gts: gts:
Triassic Lower_Triassic gts:lowerThan
subsetOf supersetOf
gts:upperThan Induan
Lopingian
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Ordinal hierarchical structure

11. TWC
Refer to and reuse existing works for definitions
Global Boundary Stratotype Section
and Point (GSSP) information
Multilingual labels
RGB codes of geological time concepts
Definitions of
geological time
concepts
Learn ideas and
take lessons from
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existing works 11

12. Annotation
function
TWC
Map: 1:625k bed
rock age of UK
1) Get a concept (e.g., Triassic) 2) Retrieve its annotation
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by clicking a feature from the ontology

13. TWC
• Based on the GTS ontology
Visualization
– ordinal hierarchical structure, labels, color codes
• Linked to WMS map layers and the GTS ontology
for annotation and filtration operations
• Tools: ActionScript and Flare library
– Result: Flash animations
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14. TWC
Flash animations
Radial tree
(“Pie”)
Rooted tree 14

15. TWC Filtration
• Show legend of a WMS map layer in the
animation
• Use the legend as a control panel to show spatial
features of certain GTS concept(s)
• Tools: JavaScript, OpenLayers and SLD
– SLD: an XML schema describing the appearance of
map layers
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16. Show Legend: SLD from WMS
TWC
1) WMS operation:
GetStyles
2) Get a list of geologic
3) Generate a Legend for time concepts from the
the WMS map layer SLD document
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17. More examples TWC
Germany
Surface rock age (1 : 1M)
Courtesy OneGeology-Europe

18. TWC Norway
Surface rock age (1 : 1M)
Courtesy OneGeology-Europe

19. TWC
Maps of participants in OneGeology-Europe

20. Denmark
TWC
Maps of participants in OneGeology-Europe
Surface rock age (1 : 1M)

21. Show features: SLD to WMS
TWC 4) Get features of
“Upper Cretaceous”
1) Click “Upper Cretaceous”
in the legend
2) Generate an SLD document
for “Upper Cretaceous”, by
referring the GTS ontology 3) Send the SLD to WMS server
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22. TWC
Filter & generalize geological time features using the legend

23. TWC
More examples of generalization
Generalization at System level Generalization at Erathem level
Generalization at Eonothem level “Precambrian” and “Phanerozoic”

24. TWC Demo
WMS + Flash Viz + Vocabulary file + JavaScript
http://goo.gl/tyDKL
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25. TWC Current work
• Collaborate with GeoSciML group to refine the
geologic time ontology
– http://resource.geosciml.org/vocabulary/timescale/
– Dr. Simon Cox (CSIRO), Dr. Steve Richard (AZGS)
• Use d3.js to rebuild the visualization
• Use triple store to hold the ontology, and SPARQL
for query
• Reuse Linked Data resources for annotation
– DBpedia, SISSVoc
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26. TWC New Demo
WMS + Flash + Ontology file + JavaScript
http://goo.gl/tyDKL
WMS + D3.js Viz + Ontology in triple store + JavaScript
http://goo.gl/WghdY
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27. TWC Wrap up
• Exploratory visualization provides a intuitive way to show
patterns of ontologies and data
• Ontology is a powerful aid for conducting exploratory
visualization
• Semantic Web provides a space for retrieving more data
and, hopefully, more information
• Further efforts are needed to deploy exploratory
visualization in earth science works
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28. TWC
Thank you!
Acknowledgements:
Demos: More information:
http://goo.gl/tyDKL Marshall X Ma
http://goo.gl/WghdY max7@rpi.edu