The National Geomagnetic Initiative (1993) / Chapter Skim
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B2: Data Management Systems
B2: Data Management Systems
Pages 190-207
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From page 190... ...
With the advent of distributed computing systems, data centers will not only be repositories of archived data physically residing in such centers, but even more importantly they will become the information and management vehicle that will enable scientists in all disciplines to locate the data they need more easily and efficiently. This is especially important for the needed interdisciplinary studies that will require a relational data base of such files.
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From page 191... ...
Finally, there will be the spacecraft operators and electric power system operators or makers of sensitive microelectronics for whom large, rapid changes in the geomagnetic field are a potential source of disaster because of their effects on sensitive technology. All of these groups will have a common need for access to high-quality geomagnetic data collected with accurate instruments at key locations, processed to comparable
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From page 192... ...
How can data centers maintain an active role throughout such a project, keep abreast of the activities that generate data, coordinate documentation, and arrange transfer to an archive? How can centers be made aware that some
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From page 193... ...
Limited accessibility may be a consequence of the physical characteristics of the media containing the data (for example, analog magnetograms on paper or strip charts held as rolls stored in a closet)
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From page 194... ...
Developments in technology have revolutionized the ability to collect and analyze data. Understanding of the physical processes that couple the solar wind and the geomagnetic field has progressed to the point that solar wind data are critical for driving magnetospheric models and making accurate forecasts of impending activity.
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From page 195... ...
Often a research project will collect a large amount of data, use only a small portion of it for the intended purpose, and then disregard or dispose of the entire data set. Until recently, few research programs have taken the necessary steps to document their data sets by providing accounts of such factors as the type of data being collected, technical specifications of the instruments that were used, the temporal and spatial resolutions of the observations, or even how the data are being stored, and few research programs have seen to it that the data are archived at some publicly accessible archival center.
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From page 196... ...
It is even less likely they know the type of magnetic data being recorded, the spatial resolution, sampling rates, instrument sensitivity, status of the data, principal investigator, or how to obtain the data. In addition to temporary campaigns, there are many ongoing geomagnetic data bases that may be more familiar to the research community, such as the USGS magnetic observatory network, the NGDC worldwide digital data collection, and the magnetic models produced by the USGS, U.S.
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From page 197... ...
This is certainly not an easy matter to resolve, but the effort needs to be made to standardize the formats of geomagnetic data as much as possible in order to minimize the need for multiple data access software programs, minimize the potential for error in retrieving these data, and maximize the availability and ease of use. In addition to formats, there is also a need to standardize data base storage media and take advantage of advancements in technology that offer small, high-volume, high-density, low-cost, and easy-to-use data storage devices that ensure the preservation of data bases for decades to come.
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From page 198... ...
The most important new scientific understandings of the nature of the Earth's core processes and their relationship to other phenomena need to have data available covering as early times as possible. Magnetic declination data from ship observations date back at least to the fifteenth century (it should be noted that these data were collected for completely practical, operational reasons, but today they serve as research tools)
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From page 199... ...
Observations that are less time-dependent, such as aeromagnetic and shipborne survey data, become meaningful only when surveys conducted over many years by numerous institutions become available in an archive for syntheses, analyses, and research. Preparation and analysis of these survey data require access to accurate local, regional, and global magnetic field models, and to dynamic models that provide a reference for moment-to-moment change throughout the day.
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From page 200... ...
· Many paper records are deteriorating. The types of geomagnetic data that need to be considered for archiving include those from repeat stations, satellites, paleomagnetism, archaeomagnetism, observatories, aeromagnetic data, ship-towed data, sea bottom instruments, land surveys, historical compass readings, anomalous compass reading reports, electromagnetic data, rock properties, and perhaps others.
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From page 201... ...
Data Access This section considers some of the technical issues involved with providing scientific access to magnetic field observations. For this discussion it is assumed that the data are available in digital form.
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From page 202... ...
Systems for the distribution of on-line data and for distributed inventory tracking are becoming common. Network access is now worldwide, and the low data rate associated with magnetic field observations (whether from ground observatories or spacecraft)
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From page 203... ...
a new family of indices based on magnetic power spectra at local observatories should be developed; (2) the suite of AE indices should be computed at I-minute resolution from an improved spatial distribution of digital stations; and (3)
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From page 204... ...
The second category, models of externally caused fields, includes magnetospheric and ionospheric models. The third category includes models of the crustal field, maps of magnetic anomalies, and data sets consisting of grid values derived from anomaly maps.
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From page 205... ...
The main challenge faced by workers in this field is how to create accurate models and charts with data that are often less than ideal. Other challenges include improving forecasts of secular variation; providing better access to models, mode!
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From page 206... ...
· Nodes for data processing, quality control, analysis, and distribution are necessary at institutions performing research. However, strong support to the national archive centers must be maintained to provide standard and custom user services and especially to capture and archive data that would otherwise be lost.
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From page 207... ...
Funding agencies should support long-term visits of research scientists to national data centers to perform cooperative analysis of the data and to provide a strong link between the data centers and the research community. Representatives of data centers should periodically visit active research and data collection organizations to assure that the needs of these organizations are being met and to arrange for any special assistance that the data center could offer to support the research and flow of data.
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