K. McDonald, B. Stroozas, B. Antia, B. Roberts, K. Chen, N. Craig, and C. Christian
Center for EUV Astrophysics, University of California 2150 Kittredge Street, Berkeley, CA 94720--5030
NASA's Extreme Ultraviolet Explorer ( EUVE) satellite was launched on 1992 June 7. In the more than two years since, EUVE has performed exceedingly well, obtaining hundreds of gigabytes of scientifically invaluable data, which researchers will continue to analyze for years to come. Among the exciting early scientific results are the first complete EUV all-sky survey, the first EUV images of extended objects (e.g., the Moon, the Vela and Cygnus supernova remnants, and the Jupiter-Io plasma torus), and the first detection of helium on Mars.
The EUVE Science Archive at the Center for EUV Astrophysics (CEA) at the University of California, Berkeley, has been established to efficiently archive and disseminate to the public the large amounts of EUVE data and its associated software and documentation. The Archive has been actively working to implement innovative ideas and technologies, building the infrastructure to store and provide easy access to EUVE archival material. One such innovative idea is the use of the World Wide Web (WWW).
The WWW provides a simple, fast, efficient, and user- and developer-friendly environment for the global dissemination of EUVE archival material. The CEA WWW site offers a variety of Archive services for EUVE data, software, documentation, and general information, as detailed in the following sections.
One of the major functions of the Archive is to provide researchers with access to EUVE data. Proprietary data rights for EUVE observations began to expire in early 1994. In 1994 August, the data from the survey phase of the mission was released on the WWW via the following services:
The proprietary data rights for the individual guest observer (GO) observations began to expire in 1994 April; additional data sets continue to be released on a monthly basis. Since the GO data sets typically require hundreds of MB of disk space to process and analyze, the Archive has developed the EUVE Spectral Data Browser service that allows users to browse, preview, and retrieve the public one-dimensional spectra. The spectral browser provides search capabilities (e.g., search by position and/or source classification) that enhance the usability of the browser by helping researchers quickly and easily locate those sources that match their particular interests. For those researchers requiring additional data for these observations (e.g., images, QPOE files, and telemetry tables), the full GO data sets may be ordered via WWW forms and are delivered on magnetic tape via postal mail.
Work is in progress to provide a variety of additional services including a complete standard set of skymap images, a standard set of pigeonholes for cataloged sources, more complete on-line access to the GO data sets (e.g., images and telemetry tables), and access to long-exposure imaging observations from the EUVE Right Angle Program (RAP---those observations taken concurrently during GO observations using the ``scanning'' telescopes, which are mounted at right angles to the GO spectrometers). Analysis services (e.g., light curves from pigeonhole data) are also under development.
In addition to providing EUVE data, the Archive is committed to implementing various software services to complement the available data. The long-term goal is to serve as a ``clearing-house'' for software contributed by external users to support EUV-related research. Toward that end, the following tools are currently available:
A wide variety of documentation and information is also available to round out the public EUVE archival material. This material includes (1) general information on EUVE, CEA, and the Archive, (2) CEA publications, including the EUVE bibliography, journal and conference abstracts and papers, the special EUVE edition of the Journal of the British Interplanetary Society (JBIS, 1993), and past editions of the EUVE electronic newsletter, and (3) form-based services for such activities as ordering EUVE CD-ROMs and archival data sets or for contacting Archive personnel. Examples of some of the information services under development include a ``meta-index'' for the Archive and a Guest Investigator (GI) Program. The Archive meta-index will fully describe and link together all the public EUVE and associated data (e.g., finding charts and spectra from the optical identification program), providing an efficient and easy-to-use database containing all the available information for EUVE sources. The GI program is being implemented to provide data analysis services to the research community by offering a standard package of support (e.g., computer access and scientific/technical personnel) to assist researchers in exploring the scientific potential of the EUVE data sets.
The EUVE Science Archive is using the WWW as the cornerstone for disseminating EUVE archival material. A wide variety of on-line electronic services provide access to large amounts of public EUVE data as well as to related software and information. As the project continues to mature, additional WWW services will be made available in order to assist the research community with the efficient and maximal use of EUVE data. For additional information, contact the Archive at the following address:
EUVE Science Archive
Center for EUV Astrophysics, University of California
2150 Kittredge Street, Berkeley, CA 94720--5030
510--642--3032 (voice) or 510--643--5660 (fax)
The authors would like to thank Prof. Stuart Bowyer, Dr. Roger F. Malina, and the EUVE science team for their general support. Special thanks go to Bill Boyd and Steve Chan for their assistance in the Archive WWW efforts. This work has been supported by NASA contract NAS5--29298.
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