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The Perspective of Virtual Observatories Supporting Space Weather Research and Operations. Peter Fox Tetherless World Constellation Rensselaer Polytechnic Institute USA. Background. Scientists should be able to access a global, distributed knowledge base of scientific data that:
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The Perspective of Virtual Observatories Supporting Space Weather Researchand Operations Peter Fox Tetherless World Constellation Rensselaer Polytechnic Institute USA
Background Scientists should be able to access a global, distributed knowledge base of scientific data that: • appears to be integrated • appears to be locally available But… data is obtained by multiple means (models and instruments), using various protocols, in differing vocabularies, using (sometimes unstated) assumptions, with inconsistent (or non-existent) meta-data. It may be inconsistent, incomplete, evolving, and distributed And… there exist(ed) significant levels of semantic heterogeneity, large-scale data, complex data types, legacy systems, inflexible and unsustainable implementation technology
Diversity, Integration, Size, … • Not just large (well organized, long-lived, well-funded) projects/ programs want to make their data available, individuals as well • Data policies: highly variable or non-existent; affects users • How can data be managed to solve challenging scientific, application or societal problems without the continued need for a scientist or other end user to know every detail of complex data management systems?
Diversity, Integration, Size, … • Scientific data repositories: • Most data still created in a manner to simplify generation, not access or use • Very diverse organization of data; files, directories, metadata, emails, etc. • Source/origin management is driven by meta-mechanisms for integration and interoperability (but still need performance) • Virtual Observatories • Data Grids • Increasing realization: need management for all forms of ‘data’, I.e. virtual data products are becoming the norm • Size matters; personal data management is as big, or a bigger problem as source data management
Virtual Observatories • Conceptual examples: • In-situ: Virtual measurements • Related measurements • Remote sensing: Virtual, integrative measurements • Data integration • Managing virtual data products/ sets
Virtual Observatories Make data and tools quickly and easily accessible to a wide audience. Operationally, virtual observatories need to find the right balance of data/model holdings, portals and client software that researchers can use without effort or interference as if all the materials were available on his/her local computer using the user’s preferred language: i.e. appear to be local and integrated
But .. Data has Lots of Audiences Information Information products More Strategic Less Strategic Scientists too! From “Why EPO?”, a NASA internal report on science education, 2005
Data is Important in non-expert situations (e.g. Space Weather Operations)!! • Data is a critical component for understanding how science works and broader applications. With it, we can: • Design and conduct scientific investigations • Make decisions • Understand the quality of data and the role of uncertainty in results • Focus on quantitative analysis and reasoning • Explore tools for visual representation • Virtual Observatories provide new mechanisms for collecting, manipulating, and aggregating data, information and information products. They also provide the opportunity for new kinds of student and non-expert experiences.
What is a Non-Specialist Use Case? Someone should be able to query a virtual observatory without having specialist knowledge E.g. Teacher accesses internet goes to An Educational Virtual Observatory and enters a search for “Aurora”.
What should the User Receive? Teacher receives four groupings of search results: 1) Educational materials: http://www.meted.ucar.edu/topics_spacewx.php and http://www.meted.ucar.edu/hao/aurora/ 2) Research, data and tools mediated for them via VOs, knows to search for brightness, or green/red line emission 3) Did you know?: Aurora is a phenomena of the upper terrestrial atmosphere (ionosphere) also known as Northern Lights 4) Did you mean?: Aurora Borealis or Aurora Australis, etc.
Shifting the Burden from the Userto the Provider (with the help of VxOs)
? Early days of VxOs - alas there shall be more than one! VO2 VO3 VO1 DBn DB2 DB3 … … … … DB1
Lightweight semantics Limited meaning, hard coded Limited extensibility Under review The Astronomy approach; data-types as a service Limited interoperability • VOTable • Simple Image Access Protocol • Simple Spectrum Access Protocol • Simple Time Access Protocol VO App2 VO App3 VO App1 Open Geospatial Consortium: Web {Feature, Coverage, Mapping} Service Sensor Web Enablement: Sensor {Observation, Planning, Analysis} Service use the same approach VO layer DBn DB2 DB3 … … … … DB1
Added value Education, clearinghouses, other services, disciplines, etc. Semantic interoperability Added value Added value Semantic query, hypothesis and inference Semantic mediation layer - mid-upper-level Added value VO API Web Serv. VO Portal Query, access and use of data 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. Semantic mediation layer - VSTO - low level Metadata, schema, data DBn DB2 DB3 … … … … DB1
Inferred plot type and return required axes data Ability to quickly plot data to assess suitability, quality, and produce a quick copy with some customization for a preliminary study. Graphics also require data management. Numerous VOs in this community
Developments for Virtual Observatories • Scaling to large numbers of data providers • Building and delivering data products that are in demand (pre-computed and on-the-fly), covering the spectrum of time latencies • Crossing disciplines and beyond science use • Data quality (propagating and explaining) • 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, processing algorithms, …) • Security, access to resources, policy enforcement • Interoperability at a variety of levels (~3)
Summary/ Discussion • The VO paradigm in is wide-spread use in Earth and Space Sciences and is increasingly able to respond to end use communities and add value to data repositories • There is an active community; meeting, publishing, developing, implementing, i.e. they are organized and many are collaborating • Standards and practices are being developed, and leveraged from other sources (IVoA, SPASE, …) • Successful implementations are in production and use (some even have evaluations) • New science and applications are being enabled and performed
VOiG 2009, Spring, Locations TBD http://www.voig.net/ (voig@voig.net)
Use cases • Who (person or program) added the comments to the science data file for the best vignetted, rectangular polarization brightness image from January, 26, 2005 1849:09UT taken by the ACOS Mark IV polarimeter? • What was the cloud cover and atmospheric seeing conditions during the local morning of January 26, 2005 at MLSO? • Find all good images on March 21, 2008. • Why are the quick look images from March 21, 2008, 1900UT missing? • Why does this image look bad?