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Ensuring the Climate Record from the NPP and NPOESS Meteorological Satellites 2 Data Systems Plans INTRODUCTION This chapter focuses on the current data processing plans of the various organizations involved in the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program, including the NPOESS Integrated Program Office (IPO) as well as NASA and NOAA's National Environmental Satellite, Data, and Information Service (NESDIS). The present satellite data systems, such as EOSDIS and the system planned for NPOESS, are designed primarily to meet needs for rapid access to small data sets, such as those for short-term forecasting. This chapter will concentrate on the present and planned operational capabilities, evaluated in the context of climate research requirements. The background material in this chapter draws heavily on presentations to the committee at its February 7-8, 2000, workshop. NPOESS AND NPP PLANS The NPOESS satellites are being designed with a wide variety of sensors that will provide data that will be used to generate 61 required environmental data record (EDR) products.1 The NPOESS sensors will be supported by a sophisticated ground data processing architecture, which the NPOESS IPO calls the Interface Data Processing Segment (IDPS). The IDPS will process data from NPOESS that will be generated at some 10 times the combined data rates of the current polar weather satellites. It will also process a plethora of data from auxiliary sources (e.g., climatology records and other satellite data, such as those from the Geostationary Operational Environmental Satellite) to produce the EDR products. Interface Data Processing Segment The NPOESS IPO is working with the NPOESS Preparatory Project (NPP) at NASA under two competing contracts for the Program Definition and Risk Reduction phases.2 The IPO expects to develop an Interface Data Processing Segment (IDPS) under a Total System Performance Responsibility (TSRP) contract starting in April 2002. Information on the IDPS was presented to the committee at its February workshop; it is summarized here to elucidate the context and limitations of the IPO's capabilities to service the science data user during the NPOESS era.3

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Goals and Objectives The IDPS would incorporate early delivery and risk-reduction relative to the nominal 2008 C1 NPOESS satellite launch by providing service for the prototype NPP spacecraft containing the NASA-supplied Advanced Technology Microwave Sounder (ATMS), the IPO-supplied Cross- Track Infrared Sounder (CrIS), and the Visible IR Imaging Radiometer Suite (VIIRS), as well as an instrument of opportunity yet to be selected. As such, the IPO is working with NASA to develop an NPP prototype IDPS capability, known for now as the Science Data Segment (SDS). The NPP prototype IDPS (alias SDS) is intended to provide early user evaluation of NPOESS data products and to allow algorithm and sensor verification and opportunities for sensor calibration and validation. Further, more than half the 61 NPOESS EDRs would be supplied by the prototype NPP capability. This would allow algorithm modifications and improvements prior to the first NPOESS launch (C1); more specifically, it would provide prototype demonstration and use of the NPOESS imager and sounder EDRs. It is important to recognize that the NPOESS program is focused entirely on the generation of EDRs; therefore, insofar as the EDRs do not meet the requirements of climate science, much of the SDS will not meet them either. Context and Interfaces The NPOESS IPO is currently conducting a phase I ground system demonstration and prototype effort with two competing contractors. Phase I efforts are providing early definition of the IDPS external interfaces, an end-to-end processing demonstration, and overall ground processing architectures and trade-offs. How these efforts progress over the next 2 years will determine if the IPO can realize its desire for an efficient, flexible, and modular system that will allow future upgrades at reasonable cost. Phase II, engineering and manufacturing development (EMD), is scheduled to start in April 2002, at which time details of the IDPS design will be available. Key Components and Functional Flow The key components of the IDPS include the following: Data ingest of raw data records (RDRs); Data processing of RDRs to sensor data records (SDRs) and EDRs; Data and EDR quality and assurance; Data management, data storage, and user access, retrieval, and distribution; and Remote field terminals.

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In accord with the NPOESS mission, the IDPS is being designed to emphasize operational user support. The program's mandate to support the operational user and the constraints imposed by the budget have resulted in plans to limit the IDPS to ingestion and processing of data on a near- real-time basis and an ability to store data for no more than 3 to 5 days, typically, and then only because some EDRs are expected to require the application over that limited time period of data acquired earlier. This limitation clearly conflicts with the needs of research data users. Open Items Although the IPO is well under way in its planning, the following key aspects of the IPO Interface Data Processing Segment have not been well defined: Comprehensive postlaunch calibration and validation of the sensors, the EDR algorithms, and the data products and Detailed NPP IDPS system definition. Unique Aspects of the NPOESS Preparatory Project Data Processing Plans NPP has been under definition for about 2 years, managed by NASA Goddard Space Flight Center. It is intended to provide data continuity between the EOS mission and the first NPOESS spacecraft launch, which will take place sometime between 2005 and approximately 2008, and to provide further risk reduction and prototype operations for critical aspects of the NPOESS mission.4 A prototype data system is being developed by the IPO with NASA and NOAA participation. The system is intended to demonstrate many aspects of the NPOESS IDPS discussed above, as well as extra climate data processing capabilities through the planned Science Data Segment. NOAA's NESDIS hopes to also provide archiving for the anticipated data needs of the research community that are not planned as part of the NPOESS IDPS. (These plans are summarized below.) Funding for these efforts is expected to be provided by NASA through the NPOESS Preparatory Project, but only for about 3 years beyond the NPP satellite launch. NPOESS Preparatory Project Mission Overview NPP is a joint effort of NASA, NOAA, and the NPOESS IPO. 5 Funded and managed largely by NASA, it has two key objectives: 1. Data continuity for EOS Terra and Aqua through the NPOESS C1 launch and

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2. Risk reduction for the NPOESS C1 mission. If the only purpose of NPP were EOS data continuity, then NASA might focus on spacecraft development and plan to use EOSDIS to process the NPP data, letting IPO develop the IDPS to process NPOESS data starting in 2008. However, NPOESS risk reduction suggests that additional effort should be devoted to preparation for NPOESS operational data processing. Accordingly, a prototype IDPS is to be available before the NPP launch to exercise critical features of the operational IDPS, as well as to provide data continuity for the research community, which will be transitioning to dependence on NPOESS a few years later. NASA is managing and funding much of the NPP effort; it is also working with the research user community because a portion of the NPP mission's data processing effort is intended to focus on provision of NPP-unique climate data processing. The NPP mission is also expected to include a NESDIS-supplied Archive and Distribution Segment (ADS) as per a pending MOU between NASA and NOAA's NESDIS. NPP Mission Priorities NPP will serve as a bridging mission from research-oriented EOS measurements to the NPOESS operational measurements, at the same time as it supports the NPOESS research component. Additionally, NPP will provide an opportunity to validate NPOESS EDRs as well as some yet-to- be-defined CDRs (see Box 2.1) and to improve operational algorithms for future use by NPOESS. It intends to rely heavily on operational agency units, such as the IPO and NOAA NESDIS, for data services. NASA, on the other hand, plans to fund CDR-specific algorithm development through competitive Announcement of Opportunity (AO) contracts to the science community. A key aspect of the NPP mission is recognition of the difference between an operational and a research mission6 and the limitations that will be imposed on the operational NPOESS mission. For example, NPOESS is expected to provide EDRs within 20 minutes of acquiring data from the spacecraft, so it will be forced in many cases to compromise the quality of the EDRs that might have been produced if tardy, but higher quality, auxiliary data were included in a more relaxed EDR production time line. While the operational community may generally find immediate data products more valuable than higher-quality deferred data products, the research community almost invariably is willing to suffer a significant product delay to ensure maximum quality. As already noted, long-term archiving is not currently planned for the operational NPOESS IDPS. The committee also notes that operational algorithms tend to be empirical and subject to regional tuning for better short-term results, while research algorithms are more physically based. For this reason, the committee believes there is also a need to provide a separate RDR to CDR processing capability for research applications. However, this capability is not currently part of the NPOESS IDPS concept. NASA has appointed an interim science panel (ISP) to help it define and develop a parallel NPP Science Data Segment to be "attached" to the developing NPOESS IDPS, with initial funding provided by NASA. It will then select an NPP science team (to replace the ISP) through a standard Announcement of Opportunity (AO) once the NPOESS sensor downselect process has been concluded in late 2000. At its February 2000 workshop, the committee was told that the science team would have about 20 members and would provide guidance to NASA on sensor and mission design, science algorithm development and CDR definition, and NPP satellite

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postlaunch algorithm validation and CDR production. The science team would also provide guidance to the IPO for improved algorithms to benefit operations as well as research applications. Appendix D describes the committee's views on science teams and their anticipated role. A NASA goal with respect to the science team effort is to delimit the AO selection based on the differentiation of EDRs and CDRs. Indeed, a primary criterion for selection will be the ability of the AO respondents to demonstrate that the proposed CDRs would contribute to climate research in a way that the NPOESS EDRs could not, while also showing that the proposed CDRs could be obtained through algorithmic evaluation of the NPOESS RDR, SDR, and EDR data stream. The committee supports the formation of science teams and has developed a set of working principles for implementing them. Its views are summarized in Appendix D. BOX 2.1 What Is a Climate Data Record? Climate research and monitoring often require the detection of very small changes against a naturally noisy background. For example, sea surface temperatures can change by several kelvin between daytime and nighttime or from year to year, whereas the climate signal of interest may change only 0.1 K over a decade. Moreover, changes in sensor performance or data processing algorithms often introduce changes greater than the climate signal. In addition to noise, spatial and temporal biases in the measurements confound climate researchers. A climate data record (CDR) is a time series that tries to account for these sources of error and noise, producing a stable, high- quality data record with quantified error characteristics. A CDR is suitable for studying interannual to decadal variability. A CDR requires considerable refinement of the raw data, generally the blending of multiple data streams. These streams may come from multiple copies of the same sensor, or they may be ancillary data fields that are used to "correct" the primary data stream. Thorough analysis of sensor performance and improved processing algorithms are also required, as are quantitative estimates of spatial and temporal errors. Starting in late 1978, nine polar-orbiting satellites carried identical copies of the Microwave Sounding Unit (MSU) to measure atmospheric temperatures. The last MSU now occupies the afternoon orbit slot (NOAA-14), while the morning slot is monitored by the Advanced Microwave Sounding Unit (AMSU) on NOAA-15. Constructing CDRs from MSU instruments has revealed that even though the instruments are essentially identical, differences among them are as large as the climate signal being sought. Once in space, each was found to have a unique response to variations in direct solar heating. Others experienced shifts in responses to onboard calibration targets. And one was found, after launch, to have been improperly calibrated in the laboratory. A final complication was due to the fact that the frequencies monitored with the new AMSU were slightly different from those monitored with the legacy MSUs. Scientists who were interested in stable, long-term temperature records from the MSU

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were required to commit considerable resources to discover problems and test adjustments. Individuals with important knowledge about the instrument were difficult to track down. Laboratory calibration information was needed and was challenging to find and decipher. When it came to verification, it was fortunate that two instruments were simultaneously operational, allowing an intercomparison of temperatures to assess the impact of the corrected data (i.e., the Earth became the common calibration target). Finally, the independent ground-based weather balloon network provided a level of confidence in the corrections. The final NPP priority, consistent with NASA's lead role in IPO technology insertion, is to engage NASA in oversight of the prelaunch characterization and calibration of NPOESS sensors, as well as vicarious postlaunch calibration and validation field campaigns. NASA intends to build on its calibration support activity for the EOS Moderate Resolution Imaging Spectroradiometer (MODIS) instrument and use the AO-funded science team to develop research-quality Level 1 algorithms. Science Data Segment According to presenters at the committee's February 2000 workshop, the SDS—at least during the NPP mission, while it is funded by NASA—will perform the following tasks: Produce and archive consistent, research-quality Level 1 products; Reprocess Level 1 data as needed after validation and feedback from Level 2+ CDR developers; Provide optional routine processing for CDR investigators funded through the AO process; Reprocess Level 2+ products based on Level 1 revisions, validation, and lessons learned; Allow for the acquisition and retention of ancillary and auxiliary data; Provide supplemental processing to aggregate research-quality EDRs into weekly/monthly, climate-grid-scale CDRs; and Distribute data only to AO investigators and a long-term archive (LTA). Further information about the NPP Science Data Segment is provided in Box 2.2.

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NESDIS DATA PROCESSING PLANS FOR NPOESS NOAA's NESDIS and its National Climate Data Center (NCDC) at Asheville, North Carolina, are working with the IPO and NASA through the IPO's team of IDPS advisory representatives to determine how the long-term archiving of CDRs and other data might be accommodated during the NPP and NPOESS missions.7 NESDIS/NASA Plans for a National Climate Data Archive and Services The basis for a national climate data archive is well established and dates to at least the National Climate Program Act of 1978 (see Appendix E).8 This act, which continues in force, tasks the Department of Commerce with providing, among other things, "systems for the management and active dissemination of climatological data and information." A statement issued in 1991 by the White House Office of Science and Technology Policy9 required that each global change parameter have at least one explicitly designated archive, and a Presidential Decision Directive issued in 199610 also required the U.S. government to produce and archive long-term environmental data sets. BOX 2.2 Science Data Segment According to NASA officials, the NPP Science Data Segment (SDS) design is intended-to the maximum extent possible within the constraints of the NPOESS budget-to at least partially transition from a NASA-funded operation to normal NPOESS operations that will utilize the Interface Data Processing Segment (IDPS). To enhance this possibility, NASA intends environmental data records (EDRs) generated by the NPOESS IDPS to be directly utilized to meet climate data record (CDR) requirements. NASA expects to cap the resources available for CDR processing to ensure that the EDR production requirements are met. However, given the experience of climate researchers (see Box 2.1), the committee believes it is unlikely that the standard EDRs will meet the quality standards necessary for CDRs, particularly in the area of data refinement and reprocessing as algorithms mature. Such reprocessing may require significant computational and storage capabilities, exceeding the requirements for EDR production. Therefore, it is probable that much of the CDR production will take place outside the context of NPP. NASA intends that the SDS only provide the necessary additional processing capability not already found in the planned NPOESS IDPS. The SDS is being planned as a relatively low-cost appendage to the IDPS to provide CDR-specific processing, in addition to long-term archiving. The committee was also briefed on plans for the development of a

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permanent Climate Data Handling System (CDHS) that would be appended to the NPOESS IDPS. However, details of how the CDHS would be funded and maintained over the life of the NPOESS mission are as yet unknown. There are currently three notional SDS architectures. One is a centralized architecture, characterized by a single CDHS located at a NASA facility (Goddard Space Flight Center, for example). At the other extreme is an option for fully distributed processing, characterized by having all the processing done by the principal investigators (PIs) selected through the NPP CDR investigator AO process. In this case, all the hardware and software for the CDHS function would be located at the PIs' home institutions, and communications would be handled via networks and other data distribution methods. The third architecture—a hybrid option—is characterized by a central CDHS that would handle various "common" PI requirements, as well as capabilities at the home institutions of the PIs that would handle PI-unique requirements. NASA presenters at the February 2000 workshop also noted that NPP would need to operate an interim ground station data acquisition capability from 2005 to 2008. This capability would incorporate direct broadcast for regional applications and would also facilitate the commercialization of NPOESS data. The ground station would perform front- end data processing to Level 0 (frame synchronization, error detection and correction, and packet reassembly), provide Level 1b+ toolkits, and provide product archive and distribution to create an infrastructure similar to that anticipated during the NPOESS era. The committee notes that the present POES system supports an enormous installed base of high-resolution picture transmission (HRPT) ground stations worldwide. The next generation of Earth remote sensing satellites, including EOS and NPOESS, will utilize higher downlink frequencies, such as X band, which are beyond the capabilities of the existing HRPT stations. Such stations have played on important role in near-real-time data transmission. Plans for the Earth Observing System (EOS) resulted in several NASA and NOAA agreements related to data archiving and dissemination. These include a 1989 NASA/NOAA memorandum of understanding applicable to ocean and atmospheric data. This MOU stated that NOAA would use its "best efforts to . . . assume responsibility . . . for active long-term archiving and appropriate science support activities . . . for the EOS program."11 In 1997, the NASA associate administrator for Earth science and the NOAA NESDIS assistant administrator agreed in an exchange of letters that the two agencies would begin to develop plans for a ground system infrastructure for U.S. climate data and services.12 Both agencies recognized NOAA as the U.S. agency charged with climate data stewardship. In 1997 and 1998, NASA and NOAA participated in a long-term archive cost modeling exercise.13 They also participated in a workshop on science and global change LTA principles and objectives,14 which they supported through the U.S. Global Change Research Program (USGCRP) Program Office, and in an LTA prototype development effort started in 1998 (and still in progress) to test the sociotechnical feasibility of a NASA-NOAA LTA. Planning for LTA

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implementation is currently under way. In September 1999, NASA and NOAA entered into negotiations on a broader MOU describing a "partnership in generating long-term climate records from Earth observation satellite data."15 NOAA and NASA representatives at the February 2000 workshop said that they plan to complete an LTA implementation plan by September 2000. Plans for Archive and Distribution Segment at the National Climatic Data Center The National Climatic Data Center (Table 2.1) is recognized by both NASA and NOAA, and by the NPP mission planners and the IPO, as the most likely repository of CDRs and other records to support climate research in the NPOESS era. However, no funding for this activity has been allocated. Nevertheless, the incremental costs of the LTA proposed for the climate research aspects of NPP and NPOESS operations are expected to be lowest if the NCDC is given enough funding to supply the capability. NCDC currently provides substantial online data access from an active (online) archive, as well as from backup, on-site and off-site, offline archives. Technological obstacles to the kind of archiving envisioned for the NPOESS era are driven primarily by projected growth by a factor of more than 20 in the amount of digital data to be collected and archived annually over the next 15 years. At the committee's February 2000 workshop, NOAA and NASA officials presented the Archive and Distribution Segment (ADS) envisioned for the NPP Climate Data Handling System and the eventual supplemental SDS and ADS to be appended to the NPOESS operational IDPS. ADS would draw specifically on NCDC's considerable experience in establishing and managing active and offline archives for business, research, and government policy analysis over several decades.16 TABLE 2.1 NOAA Data Centers Data Center Host Institution or Location Specialty National Climatic Data Center Asheville, N.C. Climate of United States Archive of weather data DMSP archivea National Geophysical Data Center Boulder, Colo. Glaciology World Data Center-A for Marine Geology and Geophysics Paleoclimatology Solar-terrestrial physics Solid Earth geophysics National Ocean Data Center Silver Spring, Md. Coastal oceanography Ocean climate Biological oceanography

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National Snow and Ice Data Center University of Colorado Snow and ice, cryosphere World Data Center-A for Glaciology a Defense Meteorological Satellite Program. NASA DATA PLANS EOS Data and Information System NASA's Earth Observing System Data and Information System (EOSDIS) manages data from NASA's Earth science research satellites and field measurement programs, providing limited data archiving, distribution, and information management services. EOSDIS is the layer that integrates the seven Distributed Active Archive Centers (DAACs) (Table 2.2) to provide seamless access to the users. Through the EOSDIS Core System (ECS) contractor, EOSDIS provides the necessary hardware and software to the DAACs to capture, process, and distribute data from the EOS satellites. Each DAAC is responsible for archival and management of data in a given scientific discipline. In their reports on site visits to the seven DAACs, NRC review panels conclude that most DAACs are serving the user community quite well and that closing any one of them would reduce NASA's ability to meet its scientific objectives.17 Since the inception of EOSDIS, the concept behind it was revised several times to reflect then- current thinking on the appropriate balance between centralized data management centers and small, heterogeneous, but flexible, federated data centers. Moreover, the EOSDIS model continues to change in response to the need to accommodate data from the small PI-led Earth System Science Pathfinder (ESSP) missions18 and the experience with the Earth Science Information Partners (ESIPs) (see Box 2.3). NewDISS NASA's Earth Science Enterprise (ESE) is in the midst of planning its data and information systems strategy for the next 6 to 10 years. This strategy is being designed to suit the new approach to Earth observations, which will include exploratory missions as well as systematic observations. To execute this plan, the ESE intends to rely on a constellation of comparatively small missions organized around critical scientific questions. This approach should be contrasted with the more centralized approach of the first series of comparatively large EOS satellites and its associated data and information system, EOSDIS. Replacing EOSDIS in the new strategy is the New Data and Information System and Services (NewDISS). NASA views NewDISS as an essential element of a plan to bring order to its Earth observations program, which will now consist of a collection of PI-driven missions, NASA facility

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missions, and long-term operational missions. Absent such a plan, it would be extremely difficult to address Earth system science questions that demand access to a variety of data sets. NewDISS intends to preserve a high level of diversity in data system participants and technical approaches rather than attempt to develop a unified system. This will require a delicate and evolving balance between preserving flexibility and maintaining a degree of predictability to support the Earth science community. The NewDISS concept would develop a set of interfaces (or rules of engagement) that would facilitate the insertion of new services and encourage new developers while maintaining critical services. Using the Internet as a model, the NewDISS concept would work to define these interfaces. Moreover, under NewDISS, the proper role of the federal government would be defined, especially as the guarantor of open access and standards and the steward of long-term data archives. TABLE 2.2 NASA Distributed Active Archive Centers Distributed Active Host Institution Scientific Specialty/ Archive Center Terra Instruments Alaska SAR Facility University of Alaska Sea ice, polar processes/none EROS Data Center U.S. Geological Survey Land processes/ASTER, MODIS Goddard Space Flight Center NASA Upper atmosphere, atmospheric dynamics, global biosphere, hydrologic processes/ TRMM, MODIS Langley Research Center NASA Radiation budget, aerosols, tropospheric chemistry/ CERES, TRMM, MISR, MOPITT National Snow and Ice Data Center University of Colorado Snow and ice, cryosphere/ MODIS Oak Ridge National Laboratory Department of Energy Biochemical fluxes and processes/ none Physical Oceanography Jet Propulsion Laboratory Oceanic circulation, air-sea NASA-Caltech interactions/ none Socioeconomic Data Archive Center CIESIN Socioeconomic data and Columbia University applications/ none

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ASTER = Advanced Spaceborne Thermal Emission and Reflection Radiometer CERES = Clouds and the Earth's Radiant Energy System CIESIN = Center for International Earth Science Information Network MOPITT = Measurement of pollution in the troposphere TRMM = Tropical Rainfall Measuring Mission BOX 2.3 The Federation of Earth Science Information Partners The Federation of Earth Science Information Partners was created by NASA's Earth Science Enterprise (ESE), in part to test assertions by scientists that the organization and even the management of data and information systems could be best accomplished by a federation of scientific users rather than a centralized activity directed by a federal agency.1 It consists of various autonomous elements that interact to deliver a complete suite of user services. Some Earth Science Information Partners (ESIPs) focus on basic data production and processing under rigorous standards of quality control, others focus on the development of new data products and services, while still others are developing services for the general public and the commercial sector. Experience to date with the Federation is encouraging, and NASA is examining this model as it develops NewDISS, a successor to EOSDIS that will be designed to better handle the PI mode of data processing expected from new, smaller, missions. _________________ 1John Townshend, University of Maryland, "The Federation of Earth Science Information Partners," Presentation to the EOS Investigator Working Group, April 2000, Tucson, Ariz. Briefing charts available online at http://www.esipfed.org/. At the committee's February 2000 workshop, NASA officials stated their intention to have NewDISS build upon the experience with the ESE Federation, which was created in response to the report of the Committee on Global Change Research (NRC, 1999). They also intend to examine the lessons learned from EOSDIS, particularly the need to foster competition in data system design and implementation. NASA Long-Term Archive Long-term archival is presently the subject of planning by the NASA Distributed Active Archive Centers. The overall goal is to develop a strategy to archive NASA data within a joint NOAA/NASA framework. The current NASA plan for EOS data is to provide medium-term access

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through the existing DAACs (Table 2.2) while the data are being used by the funded NASA science teams (3 to 10 years). The longer-term archiving and distribution of EOS data is still uncertain. Three LTA options are being considered: 1. Archive in place at the DAACs; 2. Transfer NASA data to NOAA archives19 (e.g., NCDC; see Table 2.1); and 3. A hybrid of the first two options. NASA has established study teams to explore various implementation approaches, including the data sets that should be considered, system phasing, archive services that might be provided, formats and interoperability, and joint management. NASA intends to establish a prototype in the next 12 months to test various concepts. SUMMARY Planning for NPP and NPOESS ground systems is just beginning. At its February workshop, the committee heard from NASA, NOAA, and the IPO that they plan to work together to meet the operational needs of their users. The committee was also made aware of planning activities intended to support the needs of research users to the extent possible in an operational program that is already working under a constrained out-year budget. Management of the projected volumes of data from EOS, NPP, and NPOESS will present significant challenges. Although there are substantial technical challenges, the committee believes the management and organizational challenges could be even larger-that is, having NASA and NOAA translate their plans into clear and explicit agreements on agency roles, responsibilities, and resource obligations. Absent such agreements, there is a danger that agencies will simply pass requirements from one agency to another, a clearly inadequate solution to the many challenges posed by the torrent of data anticipated from NPP and NPOESS. REFERENCE National Research Council (NRC), Board on Sustainable Development, Committee on Global Change Research. 1999. Global Environmental Change, Research Pathways for the Next Decade. Washington, D.C.: National Academy Press. 1 The NPOESS IPO defines EDRs as data records that contain the environmental parameters or imagery required to be generated as user products as well as any ancillary data required to identify or interpret these parameters or images. EDRs are generally produced by applying an appropriate set of algorithms to raw data records (RDRs). Information about the NPOESS EDRs can be found in the NPOESS Integrated Operational Requirements Document, which is available on the World Wide Web at http://npoesslib.ipo.noaa.gov/ElectLib.htm. 2 The contractors are TRW and Lockheed Martin Missiles and Space Company.

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3 Reginald Lawrence, NPOESS IPO, presentation to the committee on February 7, 2000. 4 Like POES, the NPOESS system must be designed as a launch-on-demand system. Consequently, a satellite must be operational after a launch failure or an on-orbit failure demands a replacement satellite. Based on this strategy, the first NPOESS satellite, referred to as C1, must be available by the fourth quarter of fiscal year (FY) 2008 to support any potential launch or on- orbit failure of POES-N' and DMSP F-20, which are currently scheduled for launch in January 2008 and July 2008, respectively. The first planned NPOESS launch is scheduled for the first quarter of FY 2009. 5 Information on NPP in this section and the next draws on presentations to the committee at the February 7-8, 2000, workshop by Daniel DeVito, Robert Murphy, and Joy Henegar, all of NASA. 6 National Research Council (NRC), Space Studies Board. 2000. Issues in the Integration of Research and Operational Satellite Systems for Climate Research: I. Science and Design, in press. 7 This section draws on presentations by Martha Maiden of NASA and Frank Crowe and Tom Karl of NCDC at the February 7-8, 2000, workshop. 8 The National Climate Program Act of 1978 (15 USC 2901) is available online at http://www4.law.cornell.edu/uscode/15/ch56.html#PC56. Section 108 of Public Law 101-606, "Global Change Research Act of 1990," November 16, 1990, also refers to the 1978 Act. See NRC (1999), Appendix A . 9Office of Science and Technology Policy, "Data Management for Global Change Research," Policy Statement, July 2, 1991. Available online at http://www.gcrio.org/USGCRP/DataPolicy.html. 10 National Science and Technology Council, "National Space Policy," PDD NSTC-8, September 19, 1996. Available online at http://sun00781.dn.net/spp/military/docops/national/nstc-8.htm. 11 The MOU is reproduced as Appendix B of U.S. Global Change Research Program, Global Change Science Requirements for Long-Term Archiving: Report of the Workshop, October 28-30, 1998, Boulder, Colo., March 1999. 12 Tom Karl of NCDC and Martha Maiden of NASA, "Overview of NESDIS/NASA Plans for National Climate Data and Services Including Long Term Archive," Presentation at the committee's February 7-8, 2000, workshop. 13 Ibid.

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14 U.S. Global Change Research Program, Global Science Requirements for Long-Term Archiving: Report of the Workshop, October 28-30, 1998. Boulder, Colo., March 1999. This workshop is notable for having developed key LTA guiding principles and objectives, including the following: • Facilitate the best possible science and highest-quality assessments to support business and policy decisions. • Document Earth system variability on global, regional, and local scales. • Ensure archive holdings are actively promoted and readily available. 15 Tom Karl and Martha Maiden, Presentation (see footnote 12) at the committee's Feburary 7-8, 2000, workshop. 16 NOAA representatives at the committee's February 2000 workshop indicated that the ADS needs to provide the following specific capabilities: • Data ingest, validation and archive: (1) data records, metadata, ancillary data, calibration coefficients; science products, reprocessed products, EDRs from Centrals, and concurrent ingestion of IDPS and SDS products and (2) data format, content, and metadata validation, confirmation to IDPS and SDS, and data provider coordination. • Archive management: Fulfill orders, back up and restore archive, and periodically validate archive integrity. • User interface and customer service: Electronic interactive query, search, and order services; verify payment; maintain user registration and accounts; and provide status and account information. • User product generation: Generate and ship products in a timely manner. • User product tracking and report generation: Maintain order status, generate statistical reports (such as data volume received, retransmitted, and archived and orders received, fulfilled, and pending), and report on turnaround time. 17 National Research Council (NRC), Board on Earth Sciences and Resources. 1999. Review of NASA'S Distributed Active Archive Centers. Washington, D.C.: National Academy Press. 18 The ESSP program is characterized by relatively low to moderate cost, small to medium-size missions that are capable of being built, tested, and launched in a short time. A description can be found online at http://essp.gsfc.nasa.gov/. 19 The NOAA data centers have a wider array of responsibilities, ranging from delivery of operational weather data to the National Weather Service, to the analysis and archival of weather and climate data, physical oceanography data collected by ships and satellites, coastal observations, solar-terrestrial observations, glaciology, and even marine geology and geophysics. Unlike NASA, which has a primary focus on scientific research, the NOAA data programs are primarily related to operations and user services.