CISL Annual Report 2005 > Earth System Knowledge Environment accomplishments

Virtual Solar Terrestrial Observatory (VSTO) accomplishments

NCAR/ESSL/HAO, NCAR/CISL/SCD, and McGuinness Associates are engaged in collaborative work on a new NSF-funded project called the Virtual Solar Terrestrial Observatory (VSTO). The prototype VSTO is proposed to be 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).

VSTO will comprise a system that provides virtual access to specific SSTSP data, model, tool, and material archives containing items from a variety of space- and ground-based instruments and experiments, as well as individual and community modeling and software efforts bridging research and educational use. The prototype is intended to be a fully functional system addressing a substantial need within the SSTSP community, allowing science projects to advance more rapidly.

For example, in solar coronal physics there is a need to cohesively assemble multi-wavelength images of the dynamic solar upper atmosphere. Space weather model inter-comparisons, and Assimilative Mapping of Ionospheric Electrodynamics results need to be distributed to their communities.

The overall goal is to integrate a balance of data/model holdings, portals, and client software, and a semantically rich, ontology-enabled framework that provides an environment that researchers can use without undue effort as if all the materials were available on his/her local computer. In discussions with data providers and users, the needs are clear:

"Fast access to 'portable' data, in a way that works with the tools we have; information must be easy to access, retrieve, and work with."

Too often users (and data providers) have to deal with the organizational structure of the data sets which varies significantly — data may be stored at one site in a small number of large files while similar data may be stored at another site in a large number of relatively smaller files. There is an equally large problem with the range of metadata descriptions for the data. Users often only want subsets of the data and struggle with getting it efficiently. One user expresses it as: "(Please) solve the interface problem." VSTO is aimed directly at this pressing issue that impedes scientific progress.

Datasets alone are not sufficient to build a virtual observatory. The VSTO must address the interface problem to bring data to the users' tools, and to the tools within the VSTO, effectively and in a scalable fashion. VSTO will leverage the development of schema (e.g. VSO, Earth System Grid, VHO) that adequately describe the syntax (name of a variable, its type, dimensions, etc. or the procedure name and argument list, etc.) and semantics (what the variable physically is, its units, etc. or what the procedure does and returns, etc.) of the datasets and tools, such that a new level of integration and functionality may be realized.

VSTO conceptual diagram.

During FY2005, VSTO made substantial progress in community outreach and engagement along with the development of high-level usage cases primarily aimed at the onset at the CEDAR database and the Mauna Loa Solar Observatory holdings. This has, in turn, led to the initial development of an architecture with a tiered framework, along with an evolving ontology that builds on community knowledge-development tools (e.g. Protégé, RDF, OWL, Pellet, Jambalaya) and developed in collaboration with NASA's SWEET (Semantic Web for Earth and Environmental Terminology) effort. The developed ontology currently includes classes that formalize logical concepts such as Observatory, Instrument, Parameter, Dataset, etc., and it will eventually span two disciplinary realms: upper atmosphere and solar atmosphere.

The current prototype VSTO ontology visualized with Jambalaya.

Using community tools and open-source software (e.g. Eclipse, Tomcat, Spring), the development of prototype Java class-interfaces was started with an initial focus on user interface, product selection, service composition, catalog access, data access, and semantically guided interactive visualization. A prototype portal is being developed to support the two initial use cases and will be demonstrated at the Fall 2005 AGU meeting.

The VSTO prototype tiered software architecture.