1. improve the efficiency, collaborative potential, and
The Virtual Solar-Terrestrial Observatory; access to and use of diverse solar and solar-terrestrial data (
Peter Fox1 Deborah McGuinness2 Don Middleton3, Jose Garcia1, Luca Cinquini3, Patrick West2, James Benedict2 (1HAO/NCAR) (2McGuinness Associates) (3SCD/NCAR)
Design Methodology
Develop Use Cases: for each domain, variants, generalizations and then for inter-domains
User requirements: talk to the users (often), involve them in specifying the details of the use-cases
Interface specification: user interface, data query, selection, retrieval, plotting determined in conjunction with the ontology development, web services (WSDL and OWL-return type)
Architecture design: derived from use case workflow, interfaces, user requirements
Tools and technology: Protégé, SWOOP, Jena, Eclipse, OWL-DL, Spring, Pellet
Implement rapid prototype using: Java, SQL, OPeNDAP, ION Script/IDL
User feedback: solicit and merge back into use case, user requirements and design for next iteration. Iteration is essential as ontology development is incremental and also involves users/experts.
Virtual Observatory Concept
Virtual Observatories can provide access to vast stores of scientific data: observations and models. As these electronic stores become widely used, there is potential to
improve the efficiency,
interoperability,
collaborative potential, and
impact
of a wide range of interdisciplinary scientific research. In order to realize this potential, technical challenges need to be addressed concerning (at least)
representations and interoperability of data, access, and usability.
In the Virtual Solar Terrestrial Observatory (VSTO) project, we provide an electronic repository of observational data spanning the solar-terrestrial physics domain. VSTO is a distributed, scalable education and research environment for searching, integrating, and analyzing observational, experimental and model databases in the fields of solar, solar-terrestrial and space physics (SSTSP) and utilizes semantic web technologies. We are also implementing tools and infrastructure for accessing and using the data. Our main contributions include the repository, infrastructure, and tools for the particular solar terrestrial physics as well as the design and infrastructure that may be broadened to cover more diverse science areas and communities of use.
VSTO is an NSF-funded joint effort between the High Altitude Observatory and the Scientific Computing Division at the National Center for Atmospheric Research (NCAR) and McGuinness Associates Consulting.
VSTO Generic Workflow Use Case
Each data query method is available as a semantic web service, using semantic constraints and full reasoning - returns OWL.
Data retrieval using partial of full constraints is also provided by a web service - returns URLs to the data.
Select Data
Semantic filters allow restriction of choices; and part of the ontology class hierarchy is exposed for selection.
Data integration/plotting
Graphic generated by two services with inferred information about independent variables and which ones to use for this dataset.
VSTO Architecture
Refine with inference
During selections, many choices are inferred and filled in for the user when the final query for data is made.
Final Selection
After selections, possible ways to plot the parameter(s) of interest are inferred and presented to the user.
Significant results
Use cases are from upper atmospheric physics and solar atmospheric physics. The entire class and property structure for observatory, instrument, data service, etc., developed for the first use-case, carried over immediately to the second, with a few minor additions. The instrument and parameter class hierarchy was populated and properties were added.
We use a declarative specification of the data available from the domain knowledge. The specification is query- able and much more flexible than the hard coded, static interface of the past. Three workflows for different science domains were easily merged.
Straightforward integration with existing catalogs (SQL), data retrieval (OPeNDAP) and plotting (ION/IDL, images), supported very rapid prototyping.
Web service interface to query and data retrieval are available
The implementation REPLACED the current CEDARWEB and MLSO functionality in September with a much more flexible and reusable infrastructure. The next step will be to enhance the current implementation to expose more of the functionality to the user in a context dependent and user-dependent manner thus allowing the user to have more control and flexibility over his/her tools.
Inference on plot types using the ontology, provides strong motivation for adding properties, more classes, etc.
GLOSSARY:
CEDAR - Coupled Energetics and Dynamics of Atmospheric Regions, cedarweb.hao.ucar.edu
MLSO - Mauna Loa Solar Observatory, ACOS - Advanced Coronal Observing System, mlso.hao.ucar.edu
OPeNDAP - Open-source Project for Network Data Access Protocol,
Currently implementing: Find data which represents the state of the neutral terrestrial ionosphere anywhere above 100km and toward the Arctic Circle during periods of high geomagnetic activity
Cross domain use case - reasoning on associations between: geo- magnetic activity and time, instrument operating mode and sampling altitude and location of observatories.