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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. 38
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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: