Title: The Virtual SolarTerrestrial Observatory and SPASE
1The Virtual Solar-Terrestrial Observatory and
SPASE
- Peter Fox
- HAO/ESSL/NCAR
- VSTO team
- Deborah McGuinness, Luca Cinquini, Patrick
West, Jose Garcia, Tony Darnell, James
Benedict, Don Middleton, Stan Solomon - McGuinness Associates
- Knowledge Systems and AI Lab, Stanford Univ.
- SCD/CISL/NCAR
2Outline
- VSTO introduction
- VSTO status
- Role of semantics
- SPASE considerations
- Final remarks
3VSTO Introduction
- Datasets alone are not sufficient to build a
virtual observatory VSTO integrates tools,
models, and data (real and virtual) - VSTO addresses the interface problem, effectively
and scalably - VSTO addresses the interdisciplinary metadata and
ontology problem - bridging terminology and use
of data across disciplines - VSTO leverages the development of schema that
adequately describe the - syntax (name of a variable, its type, dimensions,
etc. or the procedure name and argument list,
etc.), - semantics (what the variable physically is, its
units, etc.) and - pragmatics (or what the procedure does and
returns, etc.) of the datasets and tools. - VSTO provides a basis for a framework for
building and distributing advanced data
assimilation tools
4Integrative use-cases
- Find data which represents the state of the
neutral atmosphere anywhere above 100km and
toward the arctic circle (above 45N) at any time
of high geomagnetic activity. - Translate this into a complete query for data.
Was all the needed information recorded? - Information needs to be inferred (and integrated)
from the use-case - What is returned Data from instruments, indices
and models.
5VSTO Status
- Semantic framework developed and built with a
small team in a relatively short time - Production portal released, includes security,
etc. with full community migration (and so far
endorsement) - VSTO ontology version 0.4, (vsto.owl)
- Web Services encapsulation of semantic interfaces
being documented - More use-cases to drive the completion of the
ontologies - filling out the instrument ontology
6VSTO - semantics and ontologies in an operational
environment vsto.hao.ucar.edu, www.vsto.org
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10SPASE considerations
11Importance of (interface) stds - early days of
VxOs
VO2
VO3
VO1
DBn
DB2
DB3
DB1
12The Astronomy approach
- VOTable
- Simple Image Access Protocol
- Simple Spectrum Access Protocol
- Simple Time Access Protocol
VO App2
VO App3
VO App1
VO layer
DBn
DB2
DB3
DB1
13VO3
VO2
VO1
Query, access and use of data
Semantic mediation layer - VSTO - low level
SPASE
Metadata, schema, data
DBn
DB2
DB3
DB1
14Semantic Mediation Layer
- Ontology - capturing concepts of Parameters,
Instruments, Date/Time, Data Product (and
associated classes, properties) and Service
Classes - Maps queries to underlying data
- Generates access requests for metadata, data
- Allows queries, reasoning, analysis, new
hypothesis generation, testing, explanation, etc.
15What is an Ontology A branch of study concerned
with the nature and relations of being, or things
which exist. A formal machine-operational
specification of a conceptualization.Semantic
Web an extension of the current web in which
information is given well-defined meaning, better
enabling computers and people to work in
cooperation, www.semanticweb.org
Thesauri narrower term relation
Frames (properties)
General Logical constraints
Formal is-a
Catalog/ ID
Informal is-a
Formal instance
Disjointness, Inverse, part-of
Terms/ glossary
Value Restrs.
based on AAAI 99 Ontologies panel McGuinness,
Welty, Ushold, Gruninger, Lehmann
16Plan To annotate this with SPASE mapping
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18Final remarks
- VSTO in production, diverse datasets, robust
semantic framework - SPASE mapping into VSTO
- Some progress but not complete
- Publish results and a report
- Will be looking for a few SPASE-ready datasets
- SPASE and interoperability - partial solution
- Contact pfox_at_ucar.edu
19Additional slides
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22Why we were led to semantics
- When we integrate, we integrate concepts, terms
- In the past we would ask, guess, research a lot,
or give up - Its pretty much about meaning
- Semantics can really help find, access,
integrate, use, explain, trust - What if you
- could not only use your data and tools but remote
colleagues data and tools? - understood their assumptions, constraints, etc
and could evaluate applicability? - knew whose research currently (or in the future)
would benefit from your results? - knew whose results were consistent (or
inconsistent) with yours?
23Issues for Virtual Observatories
- Providing for multiple VOs consider
federating/aggregating rather than one-on-one - Scaling to large numbers of data providers
- Crossing disciplines
- Security, access to resources, policies
- Branding and attribution (where did this data
come from and who gets the credit, is it the
correct version, is this an authoritative
source?) - Provenance/derivation (propagating key
information as it passes through a variety of
services, copies of processing algorithms, ) - Data quality, preservation, stewardship, rescue
- Funding for participation - how to leverage
existing efforts - Interoperability at a variety of levels (3)
Semantic Web ontologies, reasoning, etc. are one
approach to address many of these issues