Access to ESE and EOS Data and Information
By Timothy Gubbels, Ph.D., and Martha Maiden, Ph.D.

The progressive operational deployment of EOSDIS over the last few years marks a major milestone in NASA's new way of doing business. The vision and primary driver of EOSDIS' Core System is that it serves as a universal ground system that allows new instruments, missions, platforms, data types, algorithms, software, and hardware to "plug and play," thus maximizing reuse of investment. A secondary driver is that the system facilitates interdisciplinary collaboration by enabling data discovery and inter-use across disciplinary boundaries. Scientists and application users unfamiliar with the details, or even the existence of a data set, are able to discover new data, search and order within an inventory, obtain extensive data documentation, and upload the data and information into their own computer systems with ease. The third challenging driver is to handle an unprecedented new scale of downlinked data, data throughput, and the size of archives. The present technical baseline calls for approximately 2.3 Terabytes (Tbytes) per day for production throughput and archive. At these rates, the archive will reach 1 Petabyte (1,000 Tbytes) by 2001. A single day's production and archive would fill over 3,500 CD-ROMs. Stacked one on top of another, the CDs would make a stack over 35 meters high, the height of an 11-story building.
    Data and information management systems to capture, process, archive, and distribute data sets are a critical element of Earth Science Enterprise. The facilitation of efficient access to ESE data and information products is a top-level driver for all of these data systems. The data and information systems can be divided into four discrete elements: 1) the Distributed Active Archive Centers (DAACs) of the present EOSDIS; 2) the Earth Science Information Partners (ESIPs); 3) the Regional Earth Science Application Centers (RESACs); and 4) dedicated and legacy systems located at the NASA centers.

DAACs and the Present EOSDIS
The Earth Observing System (EOS) Data and Information System (EOSDIS) is one of three fundamental elements of EOS-the other two consisting of the EOS satellite constellation and the EOS interdisciplinary science research program. DAACs are the physical installations of EOSDIS. EOSDIS is responsible for six major functions, including data capture and telemetry processing, spacecraft command and control, product generation, data archive management and distribution, information management, and user support.
    A working prototype with some operational elements, known as EOSDIS V0, was first deployed in 1994 and is still operational. This system provided the first interconnection across different Earth science data systems via electronic networks, interoperable catalogs, and common data distribution procedures to provide better access to existing and pre-EOS data. V0 serves a user community of over 15,000, supporting over 600 data sets in a 125 Tbyte archive, and each month fills data orders to approximately 2,300 distinct users, providing nearly 4 Tbytes of data. Version 1, consisting of extensions of Version 0 at the Goddard and Langley DAACs, has been providing full support for TRMM since its launch in November 1997. Version 2 will come alive at the time of the Landsat 7 launch in April, and provide users with access to Landsat 7, EOS AM-1, data, and information from all subsequent EOS missions. The Web-accessible user interface is based on the original V0 interface, and is known as the "EOS Data Gateway."
    The EOSDIS can be considered a large, Internet-accessible, digital library that provides "one-stop shopping" for data, information, and services across DAACs. Users will access the system by opening up a Web browser and entering the URL for the EOS Data Gateway, the primary user interface. Using the EOS Data Gateway, and related tools such as the Global Change Master Directory (GCMD), and other DAAC-specific tools, users will be able to perform a wide variety of tasks. Examples of client services include: ¥ Registering your identity to the system (user registration) for the purposes of accounting, billing, order tracking, user services assistance, and recovering session history. ¥ Viewing high-level descriptions in order to identify current data collections, available services, or data providers of interest. (The user that wishes to provide data or services may submit advertisements to the system.) ¥ Performing a guide or document search to obtain documentation on data and services. Also, conducting searches for term definition and valid search parameters. ¥ Performing inventory search for specific data objects, orgranules. Searching by spatial location, time range, parameter, or attribute. ¥ Ordering data, receiving order confirmation, cost and delivery time. ¥ Placing a subscription to future data. ¥ Browsing image samples of data, using browse to select the desired granule. ¥ Subsetting one or many granules.
    Just as desktop software is often challenging to use in the absence of customer support, the user support function of DAACs cannot be overemphasized. All support questions regarding either the data or use of the system should be directed to DAAC user services. They are accessible via E-mail or telephone; the respective E-mail addresses and telephone numbers can be accessed from either DAAC URL, the Version 0 interface, or EOS Data Gateway interface. (See http://harp.gsfc.nasa.gov/~imfwww/pub/imswelcome) Other DAAC-specific information and data and service descriptions can be obtained directly from the DAAC Web-pages, which can also be accessed through the Version 0 or EOS Data Gateway interfaces.
    EOSDIS and DAACs will provide users with open and unrestricted access to data and information holdings within the system and the pricing for EOS data products will be based on the marginal cost of reproduction. Where EOSDIS provides data supplied by an international partner or other agency, EOSDIS will apply the agreed terms in the relevant memorandum of understanding.

ESIPs
Parallel with the operational EOSDIS, NASA is evaluating working prototypes for next-generation product formation, publication, and user services for EOSDIS. Two cooperative agreement notices were issued in 1997 with the goal of developing a Working Prototype Federation (WP-Federation) of Earth Science Information Partners (ESIPs). The objective of the WP-Federation is to experiment with and evolve processes to make Earth system science data easy to preserve, locate, access, and use for all beneficial applications, including research, education, and commercial, many of which may cross the WP-Federation membership.
    There are three types of ESIPs. Type 1 ESIPs are responsible for standard data and information products whose production, publishing/distribution, and associated user services require considerable emphasis on reliability and disciplined adherence to schedules. Type 2 ESIPs are responsible for data and information products and services in support of Earth system science (other than those provided by the Type 1 ESIPs) that are developmental or research in nature, where emphasis on flexibility and creativity is key to meeting the advancing research needs. Type 3 ESIPs are those providing data and information products and services to users beyond the global change research community who enter into joint endeavor agreements with NASA's ESE.
    The initial set of working prototype Type 2 and Type 3 ESIPs was selected in 1997. DAACs fulfill the present role of Type 1 ESIPs. Type 2 ESIPs now in development support Earth system science research by producing and publishing/distributing environmental information products and by providing user services. They are also developing and demonstrating new technologies that will either extend the capabilities of or enhance the evolution of EOSDIS. Type 3 ESIPs now in development will extend the use and application of ESE data and information to users beyond the research community. They are charged with improving the access and expanding the relevancy of science results and data to the value-added industry, universities, non-profit organizations, and the general public. They are in the process of transforming science products into application-oriented information products.
    The WP-Federation is new and offers exciting potential to users. At present, the WP-Federation does not have integrated system-wide search and order capabilities. Newly produced data sets are advertised by the GCMD.

RESACs
In the fall of 1998, NASA established a set of nine Regional Earth Science Applications Centers (RESACs) designed to apply remote sensing and attending technologies to well-defined problems and issues of regional significance. The RESACs are focused on two areas: multisectoral, region-specific studies and sector-specific problems.
    The multisectoral, region-specific studies cover sets of issues that have been identified by the user community as having economic and policy consequence to their region, such as those that have arisen through the Regional Workshops of the U.S. Global Change Research Program (USGCRP). (See www.usgcrp.gov) Regional assessments are now being initiated to determine the potential consequences of global climate change/variability and to identify impacts and response options. RESACs may provide critical support to one or more of these regional assessments.
    Sector-specific problems that are associated with an easily-identified user community covering a broad region (e.g., forest managers of the Southeast; water resource managers of the Southwest; urban and regional planners of the Northeast; farmers and ranchers of the Great Plains). RESACs might assist the USGCRP national assessment in study of one or more of the sectors and/or might address an applications problem, or set of related applications problems, that confronts the selected community or sector (e.g., stream flow predictions for real-time use by water resource managers).
    The centers are comprised of end-to-end consortia (from user needs definition to product delivery) and include members from the research community, private industry, public agencies, and other potential information users in the public and private sectors. The selected consortia involve over twenty private companies, about ten state and local government agencies, twenty Federal agency regional offices, and fifteen universities.
    These consortia apply state-of-the-art NASA Earth science research results to such diverse areas as precision farm management, monitoring of forest growth and health, regional water resources and hydrology, assessment of the impact of long-term climate variability and change, land cover and land use mapping, agricultural crop disease and infestation detection, management of fire hazards, watershed and coastal management, environmental monitoring, and primary and secondary science education. It is expected that the direct infusion of the resultant applications and technologies will spur further industry opportunities and application areas.

ESE Data, Information, and Services at NASA Centers
Apart from the access provided by the three institutional entities described above, a variety of specialized data sets and services can be accessed via systems located at a number of NASA centers. An excellent example of this is the data and services being provided to the community by the CRSP program at Stennis (see article by Bruce Davis in this issue). Another example is the Global Hydrology Center in Huntsville, Alabama. In general, data and information related to specific projects in progress at these centers can be accessed from the centers' Web-pages. All of the Centers can be accessed from NASA's main Web-page. (See www.nasa.com)

About the Authors:
Dr. Martha Maiden is a program manager at NASA Headquarters' Office of Earth Science (OES). Trained as a physicist, she serves as the information science specialist in the OES Science Division. Dr Maiden is currently leading a team of experts to provide a long term plan for ESE's data and information systems and services for the next 6-10 years. Dr. Timothy Gubbels is a scientist with the NASA EOSDIS Core System Project at Raytheon Systems Company in Landover, Maryland. His areas of expertise include Earth system science, remote sensing tech nology and applications, and information systems. He can be reached at [email protected]

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