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DEFINING THE ARCHITECTURAL DEVELOPMENT OF 
EOSDIS TO FACILITATE EXTENSION TO A WIDER DATA 
INFORMATION SYSTEM 
Mark Elkington$, Richard Meyer! and Gail McConaughy* 
SEarth Observation Science Ltd, Hughes Team ECS Project Office, 1616 McCormick Drive, Landover MD 20785 2 
1D&M Associates, Hughes Team ECS Project Office, 1616 McCormick Drive, Landover MD 20785"; 
¥NASA Goddard Space Flight Center, ESDIS Project Office - Code 500, Greenbelt, Maryland 
Commission II, Working Group 2 
KEYWORDS: 
ABSTRACT 
Global Change, Information Systems, Earth Observation 
To ensure that the Earth Observing System Data and Information System (EOSDIS) can play a role in earth science information 
systems that are likely to emerge in the next century, it is important that a suitable architectural direction is established from 
the outset of its development. The paper describes an open architectural concept under development by NASA for EOSDIS 
which supports site autonomy and independent, evolutionary development of components to improve the services offered to 
users. This concept is intended to ensure that EOSDIS' data sets and services can form part of a future international earth 
science system, but also offers several advantages for the future evolvability of the system itself. 
1. INTRODUCTION 
INASA's Earth Observing System (EOS) is a long-term, 
multi-disciplinary research mission to study the processes 
leading to global change and to develop the capability to 
predict the future evolution of the Earth system on time 
scales of decades to centuries (Asrar and Dokken, 1993). The 
EOS Data Information System (EOSDIS) provides computing 
and network facilities to support the EOS research activities, 
including data interpretation and modeling; processing, 
distribution, and archiving of EOS data; and command and 
control of the spacecraft and instruments. 
Although EOSDIS will eventually contain an enormous 
amount of valuable Earth science data, there are other sources 
of information that are essential to the study of climate 
change. Of critical importance are holdings of other Global 
Change agencies, such as NOAA, USGS, etc. and other 
international organizations. The Inter-Agency Working 
Group for Data Management for Global Change Data 
(IWGDMGC) are currently in the process of defining the 
Global Change Data and Information System (GCDIS) 
intended to provide linkages between data services through a 
common set of interoperability services. NASA is actively 
participating in these efforts. 
In addition, there is also a growing interest by earth 
scientists in the possibility of developing information 
systems for earth science data which not only encompass the 
major data repositories but also enables users to take an 
active part in the information system, by providing 
data/services to the system (i.e. UserDIS). This approach 
  
* The work of the first two authors was funded as part of the 
Hughes Applied Information Systems contract to NASA for 
the EOSDIS Core System Project (contract NAS5-6000) 
31 
seeks to encourage the scientific return from the investment 
in data and information systems by ensuring that the 
scientists are an integral part of the system 
Although NASA does not have the responsibility for 
developing either GCDIS or UserDIS it wants to make sure 
that its development of EOSDIS can support both of these 
evolutionary paths. This implies taking an architectural 
direction which opens EOSDIS so that it can be included 
within wider data systems and identifying architectural 
components which EOSDIS might contribute to these 
systems. The remainder of this paper discusses EOSDIS 
relative to GCDIS/UserDIS 
This paper summarizes the results of NASA's preliminary 
architectural investigation, currently in progress. This 
paper presents high level user issues related to a generalized 
data and information system followed by an outline of an 
architectural concept for such a system. This is followed by 
a discussion of the major issues that would need to be 
resolved for the development of such a system. 
2. ARCHITECTURAL ISSUES 
The nature of Global Change and earth science research in 
general lead to some key architectural drivers for a data and 
information system to support this research: 
* The organizations which participate in the network are 
autonomous entities, and the architecture should intrude 
upon autonomy to a minimal extent. For example, the 
architecture cannot dictate how organizations will 
manage their data, their networks, and their users 
internally.