Community-Wide Workshop on NASA's Space Physics Data System
Space Physics Division
Office of Space Science
December 1993
Executive Summary
Approximately 75 scientists gathered for a community-wide workshop on the
Space Physics Data System (SPDS) in early June at Rice University, Houston.
The workshop considered community needs for access to data and made
recommendations to guide NASA's Space Physics Division (SPD) in managing
space physics data in the 1990s and beyond. It was organized around four panels
(Policy, Data Issues, Data Systems, and Software). Participants were
asked to review the SPDS Concept Document (prepared by the SPDS Steering
Committee) and to register either approval or an alternative view to any or
all the ideas discussed in the document, through one or more of the
appropriate panels. In addition, the panels were charged to identify and
prioritize key requirements in their area of interest and to comment on
relevant issues of implementation.
The resulting recommendations from the four panels are broadly consistent in
the overall sense of an SPDS in areas of joint interest. The panel structure
worked well in facilitating a combined set of recommendations that constitute
a major step forward to define the scope and an approach to SPDS that would
most effectively support the NASA space physics research community while still
being realistic in an austere budget environment.
The following are the key "policy-level" observations and recommendations of
the workshop:
- It was agreed that the creation of an SPDS would help fulfill the
urgent data exchange requirements presented by upcoming new missions,
as well as preserve and improve access to critically important data sets from
both past and present programs. SPDS should support all four SPD branch user
communities (Cosmic and Heliospheric Physics; Solar Physics; Magnetospheric
Physics; and Ionospheric, Thermospheric, and Mesospheric Physics) in ways
appropriate to each of those communities. The SPD should initiate the SPDS
now, in spite of very limited funding. As the scientific productivity of SPDS
is demonstrated and recognized by a broader scientific community, NASA will
need and ought to provide significant new resources to the Division to support
SPDS.
- The five functional objectives identified in the SPDS Concept Document are
appropriate, namely:
- to curate data sets important to current or future research;
- to provide information about space physics data sets to potential users;
- to provide efficient access to the data and ancillary information;
- to enable cost-effective and efficient analysis of data; and
- to act as a focus for the evaluation and introduction of effective new
data technologies into space physics.
The most important SPDS objective now however should be to provide the
scientific research community with access to high quality data products.
Support for the dissemination of data analysis tools is important but of
secondary priority. Awareness of recent development in data management
technologies is important for SPDS but is the lowest of the five functional
objectives.
- The workshop endorsed the Concept Document's emphasis on a distributed
data system designed, developed, and operated by scientific users of space
physics data. The SPDS should make maximum use of existing facilities
including data centers, project data management units, individual centers at
Principal Investigator (PI) institutions, and existing computer networks.
The current paradigm envisions use of the NASA Master Directory to indicate
what data are available and where, the use of existing software and human
systems to retrieve data, and the uses of data format translators to import
data into an investigator's own analysis system. Funding should be awarded
competitively through peer review. In the initial stage, this could be
through an augmentation or supplement to scientific investigations selected
under existing peer review programs.
- Consistent with a philosophy of a grass-roots effort built from existing
capabilities and operating as a community-distributed service, SPDS should
emphasize the concept of "coordination" and "coordinators" as a management
approach to accomplish its larger goals. Initially, there should be Project
Coordinator(s) and Discipline Coordinator(s) representing each of the four
Space Physics Division branch-discipline user communities. The Discipline
Coordinators should be scientists within their community who presently work w
ith, and exchange, data. The Project Coordinator(s) will provide contact
between the SPDS and other NASA data systems activities, with other government
agencies and the international community as well as work with the Discipline
Coordinators. Formal SPDS management authority should remain with MO&DA
Program of the Division. It was suggested that a follow-on SPDS Users'
Workshop should be held in about a year.
- Participation in SPDS by all current and future division-related
investigations, and their Principal Investigators (PIs) during the active
phase of missions, should be encouraged. This will require recognition of
rights of PIs to a period of exclusive use of the data from their instruments.
The workshop panels also made specific recommendations in their specific areas
of interest to both requirements and implementation. Highlights and
recommendations from the individual reports (grouped by panel) are:
- In the area of Data Issues:
- For SPDS to be effective, a listing of all data sets that are available is
needed. Catalogues should contain information concerning the instrument,
satellite, format of the data, a timeline of instrument and satellite events,
and the location of the ephemeris. Directories should serve as pointers to
distributed inventories in a standard format, that contain sufficient
information to characterize the data holding to allow the average researcher
to decide whether they are appropriate and if so, to identify the parts of the
data that meet his/her particular requirements.
- To include a maximum number of participants, the use of the SPDS should
require only widely available technology and hardware and should need minimal
technical knowledge of computer systems. There should be few "requirements"
to which data suppliers or users would need to conform. However, there should
be many "suggestions" which can be used to guide those who wish to participate.
- Some criteria for determining which data sets should be a part of SPDS
include: uniqueness, the difficulty with which they were obtained, and their
potential for being lost. However, the primary criterion must be heavy use or
the possibility of heavy use. Archiving and documenting data sets must
generally assume priority over improving formats or placing data sets on-line.
Archiving Level 0 data is highly desirable.
- The curatorial role of the original institution where the PI is (was)
affiliated should be recognized and developed. SPDS should investigate the
use of universities and institutions which have mechanisms that are designed
to provide long-term curation of scholarly data bases and raw research
materials in other disciplines such as libraries and museums.
- SPDS should include non-NASA data sets such as those funded by NSF, DoE,
other federal institutions, and universities. Both US and non-US data
suppliers and users should be included. The needs of developing nations
should be considered.
- In the area of Data Systems:
- The critical system functionalities identified for SPDS are: the delivery
of self-documenting data; the existence of a matrix of translators between
several standard formats; and a network-based capability for browsing and
examining inventory records for the system's data holdings.
- Considering the austere funding environment, as well as the diversity of
systems in place at the nodes listed in the concept document and potential
subnodes, the panel specified as system level standards only TCP/IP network
interfaces and the seven file formats identified in the Concept Document as
initial system-wide standards. The overriding consideration for any SPDS
interface should be ease of use by a technically competent investigator. As
an aid to SPDS nodes developing appropriate software interfaces, the space
physics community should be polled on such subjects as preferred interface,
monitor display capabilities, data analysis software of choice, and available
data communications. SPD should express its support for NASA's efforts to lead
in the implementation technologies, such as ATM, that would significantly
increase the bandwidth of data communications with currently bandwidth-limited
sites.
- NSSDC besides continuing its traditional roles as a Master Directory
server, central data copying facility, and deep archiving facility, should
also serve the SPDS user community by providing a bulletin board and/or
mailing list for announcements of general interest, and anonymous FTP services
for data format translators, models, and other software tools of general
interest.
- In the area of Software:
- The SPDS should state a policy that new application development should
meet some minimum standards. Adherence to this policy should become a
contractual obligation. However, it is also believed that NASA's current
software development policy imposes too much overhead on software projects.
- NASA should provide funding to extend and enhance existing systems to meet
its requirements and needs. If no software currently exists that can meet
specific SPDS needs, then development of new software should be funded. SPDS
should encourage the sharing of existing software and actively work to make it
easier to obtain existing software. Freely distributed software was considered
a high priority activity, but the choice of Commercial Off-The-Shelf (COTS)
software should be left up to the individual. It was also noted that no COTS
technology assessment group should be a part of the SPDS.
- A catalog of existing software should be implemented. Providing direct
access to a central repository (library) of software is as not important as a
catalog. Software should include data processing, translation, analysis, and
visualization routines, and could include ancillary software such as models,
simulation results, etc. Acting as a software repository is not considered as
high a priority as dissemination of information, comments, and experiences.
- NASA should assume a capital equipment responsibility and provide funds to
insure that the research community has a computing environment that does not
limit the general distribution, use, and development of software systems.
However, the current hardware and operating system market is not sufficiently
stable nor influenced by the SPDS community by itself to the extent that
choosing a standard platform would be viable. It is recognized that the
current trend is towards UNIX systems that run X-windows on a variety of
architectures and Windows-NT running on Intel architectures. The emphasis
should be on developing portable code so that it may easily be migrated as
new technologies are introduced.
Since the workshop and in direct response to its recommendations, the Space
Physics Division has called for volunteers and now named an "SPDS Coordinators"
Working Group (SPDS/CWG) that will be composed of:
- an SPDS Project Scientist,
- four SPDS Lead Discipline Coordinators, and
- two SPDS Project (Co-)Coordinator(s).
The Lead Discipline Coordinators will be supported by four Discipline
Coordination Teams composed of volunteers from their communities. The Lead
Discipline Coordinators will represent the Teams on the SPDS/CWG. The
SPDS/CWG has the broad responsibility to move the definition of an SPDS
program forward from the Concept Document and the recommendations of this
workshop, to start a first working version of SPDS and to serve as focal
points for advertising SPDS, compiling and disseminating information about
available data and data access, and establishing a beginning set of "rules of
the road" for data exchange.
The prototype
SPDS
developed for the workshop remains operational. The workshop
participants in the data systems panel also defined an experiment they would
undertake to see whether DITDOS, an inventory tracking system developed by
PDS, could be used easily and inexpensively to manage existing space physics
inventories. The CEDAR project inventory established at NCAR was selected as
a test case. The Institute of Geophysics and Planetary Physics (IGPP) at
UCLA has established a list server to serve the SPDS community as a forum for
discussing SPDS related issues.
A Postscript version of the entire document.
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Authors and Curators
Robert McGuire, mcguire@nssdca.gsfc.nasa.gov, (301) 286-7794
Chief, Space Physics Data Facility
NASA Goddard Space Flight Center
Greenbelt, MD 20771, USA
Last Modified: 20 September 2002
(TJK)