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From page 25... ...
4 Data Archiving in the Science Centers THE IMPORTANCE OF ARCHIvAL ACCESS Access to archival material is becoming increasingly important for all space science disciplines because data are often analyzed more than once and because scientists combine existing data sets across traditionally separate wavelength boundaries. The science centers have become archival centers, and today these online archives serve as the primary point of access to mission data, both raw and calibrated. Not only are the archives the keepers of the raw observations, but they also provide direct access to calibrated versions of their data products, with online documentation and searchable databases linked to the literature. This "shrink-wrapped" feature of modern archives makes it easier for astronomers to combine data across various subdisciplines, a task that would have been difficult even a few years ago when all astronomers had their own sets of tools and did most of the data reduction themselves.
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From page 26... ...
PORTALS TO THE UNIVERSE The decision on where to keep a long-term archive should consider what makes an archive usable and sustainable for the community, beyond the minimal goals of preserving the bytes. The committee describes a sustainable archive as one that • Continually facilitates the production of new scientific results; • Has a strategic goal to enable more and better science; • Contains high-quality, reliable data; • Provides simple and useful scientific tools to a broad community; • Provides user support to the novice as well as to the power user; • Has many diverse uses (and users) ; • Has a core group of users for whom it is an everyday tool; • Collects metrics that track usage and science output; • Is properly curated (e.g., errors discovered are documented and fixed)
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From page 27... ...
at http://www.stsci.edu/science/goods/ -- are prime examples of collecting data at multiple wavelengths over the same area. Archival grants provided the initial motivation for astrophysicists to start analyzing archival data. Today it seems to be almost natural that many data sets are analyzed by numerous scientists, but 10 years ago this was the exception. Finding: Continued access to mission data across a broad range of wavelengths is of utmost importance to the whole community. As the use and reuse of data are crossing wavelength boundaries, it is important to consider what is necessary to support such activities. The most important capability from an astronomer's perspective is that of locating an archive that contains data from a particular region of the sky, in a particular waveband, with a particular instrument. Doing so is possible today, but the procedure is cumbersome.
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From page 28... ...
External nonproprietary retrievals FIGURE 4.1 Usage of archival data from the Hubble archive. The brown area shows PI access, roughly steady in time, while the yellow area is non-PI usage, clearly growing rapidly since 1997, following the release in 1996 of Hubble Deep Field project data. SOURCE: Megan Donahue, Michigan State University, presentation to the committee on November 18, 2005. 4-1 Finding: Software tools that use standard data frameworks such as FITS provide the best means to cross-query wavelength-specific data sets.
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From page 29... ...
DATA ARCHIVING IN THE SCIENCE CENTERS are good examples of these efforts. The upper management of the archives at the science centers has embraced this direction, and the archives are currently implementing medium-term measures to achieve VO standards. NEAR FUTURE If the current trend to strong collaboration continues, the archives supported by the science centers will form a homogeneous, easy-to-use system that is integrated from a user's perspective. Each wavelength regime, however, will retain its own responsibilities for the long-term curation and preservation of the expertise. Such a system of archives needs to be sustainable. What does this sustainability imply?
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