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Science Archives in the 21st Century


T12 - Science archives need to communicate more than data: the example of AMDA at CDPP

V. Gènot, C. Jacquey, E. Budnik, R. Hitier, M. Bouchemit, M. Gangloff, and C. Harvey, CDPP/CESR

R. Conseil, D. Heulet, and C. Huc, CNES

Topic: The CDPP (French Plasma Physics Data Centre) has developed a new service to help multi-dataset analysis and in which event lists are at the core of archive communication.

The growing size of science archives and the need for cross-disciplinary approaches foster the demand for a new type of archive communication objects, beyond ordinary data exchange. Indeed as each archive remains close to its data and retains the required expertise to use them properly, the need for complementary communication objects appears: they are added-value concepts and hold a high level of genericity. For example reduced parameters, standardized images, or event lists fall into this category. Tools are therefore needed to produce, ingest and manage these objects in archives. In the context of Space Physics, AMDA (Automated Multi-Dataset Analysis) is such a service developed at CDPP. In this presentation, we shall detail AMDA, its concept and functionalities, and some scientific results obtained in studies based on its use. In AMDA system information circulate by means of two core entities: the parameter (e.g: 'electron density', 'magnetic field vector', 'plasma beta') at the data level, and the event list (e.g: magnetopause crossings, substorm onsets) at a higher level. Around these entities, AMDA is built as a suite of integrated tools allowing to perform massive scientific processing of the content of multi-datasets. This service is designed to work with a local database or (via web-services) distant data sources. The functionalities offered in AMDA include (i) user edited visualization browse, (ii) semiautomated event search (by visual identification), (iii) automated event search (based on user edited mathematical criteria applied to the data content), (iv) data extraction, (v) user edited parameter computation, (vi) functions and models (coordinates transformations, magnetic field/magnetopause/shock models) and (vii) access to data stored in distant archives. Recently, AMDA has been used for statistical studies in the magnetosheah with data from the four CLUSTER spacecraft, and in the magnetotail with a set of data from GEOTAIL, IMP-8, ISEE, AMPTE, INTERBALL and CLUSTER missions. In the field of heliophysics it will highly facilitate the combined analysis of data from ULYSSES, STEREO, CLUSTER and THEMIS and, hopefully, of planetary data. Finally, the experience gained in designing and building AMDA sharpened CDPP look on database management in the Virtual Observatories era, and we will present the standardization needs we feel urgent to complement archive communication regarding descriptive information of data, numerical simulation and model outputs, and event lists.

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