Review of NASA's Distributed Active Archive Centers (1999) / Chapter Skim
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2 Overview of the DAAC System
2 Overview of the DAAC System
Pages 27-52
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From page 27... ...
supporting the operational ingest and management of a suite of spaceborne sensors operated as part of the Earth Science Enterprise, (2) producing data products from remotely sensed and complementary in situ data sets as required, and (3)
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From page 28... ...
For example, the ASF DAAC serves seaice scientists interested in synthetic aperture radar data, whereas the NSIDC DAAC serves the broader polar science community. Similarly, the EDC and ORNL DAACs serve terrestrial ecologists, but the EDC DAAC focuses on users of remote sensing imagery, and the ORNL DAAC focuses on users of in situ data from field campaigns and process studies.
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From page 29... ...
The GSFC, LaRC, and EDC DAACs must focus on preparing for the massive data flows from near-term missions such as the AM-1 platform. On the other hand, the NSIDC DAAC and the PO.DAAC will primarily manage data from later missions and can continue to focus on refining their service to existing users.
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From page 30... ...
In doing so, users may benefit from the results of NASA's prototype federation of Earth Science Information Partners (ESIPs)
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From page 31... ...
It is clear from the following chapters that each DAAC occupies an important, unique niche in the Earth Science Enterprise. None of the panels raise concerns about functional overlaps between DAACs or about other possible redundancies.
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From page 32... ...
Recommendation 2. A DAAC alliance with a common goal will better serve the broader community than the collection of individual centers that currently exists.
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From page 33... ...
that the new federated paradigm should meet the stated EOSDIS goals, provided the architecture is implemented in a flexible way. Indeed, with the adoption of DAAC-specific approaches to managing the AM-1 data streams, the increased participation of EOS science and instrument teams in processing data, and the initiation of the prototype federation, the move to an EOSDIS federation is timely and probably inevitable.
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From page 34... ...
the principal ESE constituencies include: · data producers, including instrument teams and scientists conducting in situ studies (e.g., scientists contributing data to the ORNL DAAC) ; · global change scientists, who use and synthesize a broad range of data from different sources, and who may also produce higher-level data products; · knowledge brokers, including policy makers, teachers, students, and the interested public, who use reliable, interpreted data products or assessments; and for-profit businesses, which generate value-added data products for commercial purposes.
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From page 35... ...
In addition, national data centers have developed strategies for keeping track of the user communities they serve, updating user profiles, and soliciting user input on the usefulness of their products. Their experience would likely provide a useful guide to the DAACs.
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From page 36... ...
The only significant dissatisfaction was expressed quite emphatically by scientific users of the ASF DAAC and, to a lesser extent, the EDC DAAC. The major sources of strong dissatisfaction, described in sometimes long essays, had to do with (1)
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From page 37... ...
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From page 38... ...
Foreign users had more difficulty accessing the DAAC's holdings than sophisticated and casual users. Again, however, a vocal minority of scientific users reported that access to the ASF and EDC DAACs is "very difficult." As noted in the second bullet, a minority of survey respondents have difficulty finding data in usable forms.
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From page 40... ...
Particularly noteworthy from this point of view are the excellent reviews that the PO.DAAC and the NSIDC DAAC received. A better day-to-day interaction with the scientific user community, however, was recommended for the EDC, GSFC, and LaRC DAACs, especially since a strong scientific community with highly relevant interests resides within walking distance in all three instances!
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From page 41... ...
In addition, most panels noted that the DAACs need to improve their relationship with the scientific user community. Like the world and national data centers that the committee reviews regularly, those DAACs that have achieved a high degree of symbiosis with a collocated group of active researchers enjoy a substantially higher level of user satisfaction than others.
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From page 42... ...
Life-cycle data management involves looking beyond immediate goals and deliverables and taking steps now in the interest of future generations of scientists and citizens to enhance their ability to make effective use of the unique and irreplaceable records that the EOS program is collecting at considerable expense. It begins with good instrument design and careful calibration, and extends through careful documentation of every step of the data processing and product generation, to reliable long-term archive.
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From page 43... ...
Also noteworthy are the pre-subsetted data sets prepared by the GSFC DAAC, which enable users to work with manageable amounts of data, and the tools for documenting data sets provided by the ORNL DAAC. Most of the other DAACs, however, have to place greater attention on subletting (LaRC and EDC DAACs)
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From page 44... ...
Its excellent document, "SeaSat Data Restoration - Lessons Learned" that it produced for this review should serve as a valuable resource to other DAACs and data centers. Finally, it is well known among data center managers that 10% of the users access 90% of the holdings, whereas 90% of the users access 10% of the holdings (generally at a higher level of data processing)
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From page 45... ...
The latter is particularly important because the unique biogeochemical holdings of the ORNL DAAC are essential to the proper validation and calibration of remotely sensed data. Unless the ORNL DAAC asserts itself, the various flight projects will be forced to develop independent solutions, and large components of the EOS program will fail.
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From page 46... ...
Conclusions and Recommendations The ultimate success of the Earth Science Enterprise will be judged not only by the immediate scientific gains that arise from use of newly collected data, but also by the ability of scientists to use the data in the long term to study global environmental change. The data are most likely to retain their usefulness in the long term if the DAACs adopt a life-cycle data management approach and become involved in everything from the collection of data to its eventual archive.
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From page 47... ...
Second, it promotes creative scientific analysis of these data and, as such, must enhance opportunities for scientists to build on the unprecedented information it already contains and on the new data anticipated over the coming decades. Third, it is the largest single component in global efforts to understand, predict, document, and mitigate the impacts of global environmental change (although key data currently reside in other agencies such as NOAA.)
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From page 48... ...
Yet each has a vital role to play in the Earth Science Enterprise and should be integrated conceptually into EOSDIS. (It is significant that NASA's model of the EOSDIS architecture divides the ORNL DAAC from the others [see Figure 1.11.)
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From page 49... ...
to collaborate to provide users with a common look and feel to the information system. The former will require close collaboration with science and instrument teams and active scientists.
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From page 50... ...
Consequently, the issue of cost-effectiveness could not be addressed in a significant way. It is noteworthy, however, that even though most of the DAAC budgets far exceed the budgets of national data centers, none of the national data center directors who served on the panels thought that the DAAC budgets were too high for the amount or complexity of data being handled, the size of the user base, or the services provided.
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From page 51... ...
In the earlier stages of data processing and distribution, the DAACs are likely to be bypassed in favor of scientists calling their instrument team colleagues. In fact, the Science Computing Facilities where the data products are being generated are likely to become the primary distribution mechanism until the instrument teams members become so fed up that they relinquish the distribution task to the DAACs.
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From page 52... ...
NASA leadership is crucial for this transformation to succeed. In the near term, NASA' s attention is necessarily focused on fulfilling existing software commitments and on supporting science and instrument teams for existing or near-term flight missions.
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