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V. USER
ILVEMENT
The fundamental requirement for an information system is to support
user needs. The complete information system, consisting of instruments,
data systems on the satellite, data downJinks, and processing on the
ground, must acquire, manage, and distribute the data. It wild take a
massive effort to have a data system in pi ace for systems such as the
Earth Observing System (EOS) in 1995. It is difficult to scale the
overall effort very weld until the systems planning and component analyses
are more advanced. However, it is cd ear that OSSA wild need to apply
considerable information systems resources to complete the task.
OSSA has shown over a lengthy period that i
its information systems users. It was at OSSA'
that the Space Science Board (SSB) of the Nations
Commission on Physical Sciences, Mathematics, anc
the Commi tame - ~ ~ - -
~ values the viewpoints of
s request, for example,
Research Council's
Resources established
. .__ ~ ~ ~11- ~V111~~ ~O ~ I On I ~ ~UUI'I^U J I r1 1~ / ~ . The
CODMAC's continuing charge is to examine the management of existing and
future data acquired from spacecraft and associated computations in the
space and earth sciences, and to make recommendations for improvements
from the perspective of the scientific user.
on Data Management and Comoutation fEnnMArl in lq7R
In its 1982 report,* CODMAC defined a set of principles and recom-
mended that those principles "become the foundation for the management of
scientific data." The first of the CODMAC principles reads as follows:
"Scientific Involvement. There should be active invo~ve-
ment of scientists from inception to completion of space
missions, projects, and programs in order to assure
production of, and access to, high-qua~ity data sets.
Scientists should be involved in planning, acquisition,
processing, and archiving of data. Such involvement will
Data Management and Computation, Volume 1: Issues and
Recommendations; Committee on Data Management and
Computation, Space Science Board, NRC; National Academy
Press, Washington, D.C.; 1982.
35
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maximize the science return on both science-oriented and
application-oriented missions and improve the quality of
applications data for application users."
In its second report,* CODMAC notes that progress had been made on the
recommendations in its first report. One example is the initiation by the
ISO of the pilot data systems, which directly involved the science
community. However, CODMAC also noted its concern that neither NASA nor
the space science community seem to be postured "to efficiently implement
geographically distributed information systems..." It observed that NASA
and the science community, with strong leadership from NASA, "need to work
together to achieve the common goad -- to maximize the scientific return
from space science data." To this end, CODMAC recommended that NASA estab-
Jish a high-level advisory group, consisting of experienced data users
(scientists) and experts in the relevant technologies, to advise senior
NASA officials "on matters of data policy (and) computation and data
management practices."
It is difficult to know just how far to go in promoting user
involvement in the entire information systems process. Clearly, OSSA has
a tremendous experience base, especially that part embodied by the users,
for the development of its information systems. The question raised by
CODMAC (and by several user-oriented members of this Committee) is whether
OSSA is taking full advantage of that which is available to it. At the
same time, the Committee recognizes that OSSA must maintain control over
its systems and related programs, plans, operations, and management
processes. Therefore, the fo1 lowing is considered to be an issue that
requires further study:
Issue #3. To what extent should users be involved in the development
of and changes to information systems, while still maintaining OSSA
control?
Users of Space-Derived Science Data. According to the second CODMAC
report, there are two types of users of space-derived science data:
-- Primary users are the principal investigators (PIs) who develop
instrumentation, their co-investigators, and researchers and
students who work directly with the PIs. The term "primary users"
also applies to members of research teams who obtain data from a
remote sensing instrument. The primary users, in general, receive
data from their instrument directly from a mission data system.
Issues and Recommendations Associated with Distributed Computation and
Data Management Systems for the Space Sciences; Committee on Data
Management and Computation, Space Science Board, NRC; National Academy
Press, Washington, D.C.; 1987.
36
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Secondary users are scientists actively engaged in research in a
given discipline, but who are not directly associated with a given
instrument. Secondary users may or may not be directly associated
with a particular mission. Secondary users usually receive data
from an archive. Also:
Primary users become secondary users when they want to use
data from an instrument other than the one with which they are
associated.
Another example of secondary users is scientists associated
with one spacecraft who wish to do correlative studies by
using data from another spacecraft. In fact, all users of
correlative data are secondary users.*
In most cases, guest investigators are considered as secondary
users.
Most commercial users of space derived data are secondary
users.
EOS Data Users. According to the EOS Data Panel, there will be at
least four types of major users of that system:**
1. Instrument team members and support personnel associated with EOS
instrument or mission operations centers. They will need to moni-
tor a sampling of data continually in near-rea] time for quality
assurance, error detection, and instrument malfunction assessment.
They should have the capability to reconfigure observational
sequences when malfunctions of special events occur.
2. Researchers, instrument team members, or operations-oriented
personnel who need instrument-specific, near-rea] time, or
rea1-time data processing, delivery, and display capabilities.
Some of these, such as the National Oceanographic and Atmospheric
Administration (NOAA) and the Department of Defense ( none menu
require large data volumes.
. . ~ , , — ~
Correlative data are data that are processed in a standard way, are
distributed to all interested scientists, and are used to interpret
data from spacecraft. An example of this is ground magnetic data used
for correlative studies in solarterrestria] physics.
** Report of the Eos Data Pane] (Robert R. P. Chase, et al.), NASA
Technical Memorandum 87777, Volume Ila, 1986, pp. v-vi.
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3. Researchers who will need to interrogate directories and catalogs
of EOS and other relevant data on an instrument, geographic Joca-
tion, and time of acquisition basis. They will need to order
data, and in some cases they wild request particular observational
sequences from EOS instruments.
4. Other researchers also will need to interrogate EOS and non-EOS
data directories and catalogs, but they are distinguished from the
previous group by the need to browse EOS data visually through
attributes or expert systems to find particular features, attri-
butes, or special cases.
OSSA-User Interaction. During this study, the Committee reviewed
background material and documentation pertaining to several missions
planned for the 199Os involving astronomy and astrophysics, planetary
sciences, solar terrestrial physics, atmospheric sciences, and land
resource sciences. The Committee found that al] too frequently OSSA
involves users early in the information system design phase, but does not
maintain a continuing dialogue with them during the development phase.
There was a strong impression, even though the Committee was sure it was
not intended, that OSSA tends to treat each mission as a new start for
information systems development.
The International Solar-Terrestria] Physics program is a case where
users have been involved in the planning in an iterative way. In that
program members of the science community worked with NASA officials to
design the data system at the same time the rest of the project system was
designed. NASA officials kept the users informed of the constraints
imposed by limited resources. They worked with the scientists to deter-
mine the trade-offs involved for the spacecraft, instruments, and data
system, and the implications of these trade-offs on the science return
from the missions. The result is a data system plan which meets all of
the user requirements but is stir] very modest in scope and cost.
An example in which OSSA does not appear to be interacting effectively
with the users is the design of the high resolution imaging spectrometer
(HIRIS), which is part of the EOS instrument package. The users requested
narrow bands and a wide selection of bands. The first report of over 50
possible bands was met with approval from the user community. Later
announcements of ilS channels--and more recently of over 220 channels of
data--were met with amazement. The Committee was unable to determine the
basis for this planning, but perhaps it is based on other user requests.
It seems likely to the Committee that earth resources scientists wild ask
for 5-7 channels of data at one time, with occasional requests for up to
15 or 20 channels, but it will be rare to see a request for 220 channels.
The data rate of instruments will have a large impact on the information
system needed to provide the data and information to the user. While the
Committee believes the supporting information system should be responsive
to the needs of the users, it hopes (in this example) that OSSA will not
design an-information delivery system based on sampling al] of the 220
channels for one scene.
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A number of strong arguments can be developed in support of involving
the users in the planning of information systems. The Committee feels the
most important of these might be to control costs by determining the
limits of the data capability that is provided to the users.
There must be sufficient data capability to obtain the appropriate
scientific, human-interest, and applied use of the data. This must be
balanced against the need within NASA to save money where practical, so
that as many valuable missions as possible can be flown. The Committee
heard reports emphasizing that it does not make sense to fly a satellite
if reasonable use of the data is not funded. The same is true of the data
system. At some point costs exceed benefits and a limit to the data
system should be defined, at least to the extent possible. Such cost-
benefit analyses cannot be rigorously performed in all cases, but the
exercise of working with the user community to define appropriate con-
straints would stand a good chance of providing the information needed for
evaluation purposes.
To help decide what level of effort is appropriate, OSSA needs to know
who the users are, what uses will be made of the data, and what scale of
user support is appropriate for a given data set. Some of the Pilot Data
Systems provide more information than the users can absorb. Many critical
research data sets are, in fact, not used by large numbers of people. For
example:
A popular set of twice-daily, southern-hemisphere atmospheric
analyses from Australia covered a lO-year period. Over a 4-year
period, copies were sent by the National Center for Atmospheric
Research (NCAR) to about 40 people at universities and other
research laboratories. Another estimated 20 scientists used it
on-1 ine. Since the first rush of research on the data, the use
has dropped off to about five requests per year, though a number
of people probably are stir] using their data copies at home.
The most popular Nimbus data set was a set of two or three tapes
having ozone samples covering 200 km along orbital tracks, active
for several years. NASA mailed out copies of these tapes to 70
users. Many satellite data sets will be used by a few people
(perhaps i-10) during a several-year period while the main
research is going on. Then the data will be relatively dormant
while the science waits for periodic new ideas and new questions.
For such data, it is mandatory to have data sets that are
wel1-structured, we11-documented, and in a catalog. In many
cases, it is not useful to spend very much money in advance of the
need to develop novel ways to display a particular data set. The
data set situation is analogous to that of books in a library.
Many essential documents are not used very often.
The National Climate Data Center, at Asheville, North Carolina, deals
with data that has a wider interest than the above data. It receives
about 50,000 requests a year, mostly for small amounts of printed data.
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Most requests can be satisfied for costs of $3 to $15 each. In addition,
many publications are distributed by subscription. Requests that demand
significant resources are much smaller in number. Only about 1,300
requests each year are for digital data. About 4,000 tape copies are
mailed each year. Sometimes these tapes go into other archives, where
they are available to even more users. The first archive is then like a
wholesaler. Many commercial firms now help to distribute weather data.
The Committee has seen that a given scientific data set may have only
5 to SO users over a few years. However, the scientists who know most
about these data may produce derived data sets that are easier for other
people to use. Examples are sea-surface temperature, atmospheric ana~y-
ses, ice concentration, and pictures. It is these products that usually
will be used in interdisciplinary science. Some of the derived figures,
summaries and pictures will go into thousands of copies of textbooks and
popular books.
Just as the system throughput must be taken into consideration when
designing the supporting information system, so should the limits of the
data systems be considered in spacecraft and instrument design. Most
scientists recognize the need for trade-offs between the data system costs
and research funding, and they are willing to participate in the develop-
ment of suitable compromises. They have a vested interest in the mission
and they have considerable experience and expertise to offer. Such trade-
offs and compromises are cheapest if they are worked out during the mis-
sion planning stage, rather than later.
Through its briefings from NASA officials, the Committee also learned
of several initiatives within OSSA's domain to find common elements in
satellite data systems, so that generic systems could be designed for use
on such missions. This is eminently sensible, since it can save money and
it can lead to an approach that will capitalize on past successes while
avoiding the pitfalls of past failures. It appeared to the Committee that
such efforts were particularly we11-developed at JPL, where common agree-
ment is reached by forming a working group of the appropriate experts from
various flight projects and the JPL ISO. If OSSA can expand these initia-
tives to involve its information systems users without compromising sched-
u~e and cost constraints, a fairly rapid solution to this issue might
evolve.
Another factor to be considered involves NASA's relationship with
operational data users such as NOAA, the U.S. Geologic Survey (USGS), the
U.S. Department of Agriculture (USDA), and other government agencies, as
well as with commercial users of space data. These communities must also
be considered when NASA develops new sensor technologies, since the result-
ing data and data products will ultimately become their responsibility.
The agricultural industry, for example, needs data based on economic trade
zones, not just county boundaries, and the petroleum industry has special
interests in geologic profiles. These operational requirements need to be
included with NASA's science and technology research objectives, to make
certain the basic data is available from which new and more useful types
of data products can be prepared.
40
Representative terms from entire chapter:
space science
