A Report of the Committee on Earth Studies1
The ability to make earth observations from space is one of the great successes of the space age. For both scientists and operational users of the data, however, this success has been tempered with disappointment. The promise of the technology has not yet been realized, nor is it evident that current activities are leading toward a timely realization of that promise. The civil earth observations programs of the National Aeronautics and Space Administration (NASA) have been in a state of annual redesign for more than 5 years. The early momentum that led to the laudable concept of NASA’s Mission to Planet Earth (MTPE) is being dissipated.
In this report the Committee on Earth Studies (CES), a standing committee of the Space Studies Board (SSB) within the National Research Council (NRC), reviews the recent history (nominally from 1981 to 1995) of the U.S. earth observations programs that serve civilian needs. The principal observations programs examined are those of NASA and the National Oceanic and Atmospheric Administration (NOAA). The Air Force’s Defense Meteorological Satellite Program (DMSP) is discussed, but only from the perspective of its relationship to civil needs and the planned merger with the NOAA polar-orbiting system.
The report also reviews the interfaces between the earth observations satellite programs and the major national and international environmental monitoring and research programs. The monitoring and research programs discussed are the U.S. Global Change Research Program (USGCRP), the International Geosphere-Biosphere Program (IGBP), the World Climate Research Program (WCRP), related international scientific campaigns, and operational programs for the sharing and application of environmental data.
It is not the intent of the CES to make detailed reviews of every aspect of this broad scope of activities, nor is it the intent to provide detailed findings and recommendations for action by responsible agencies. Instead, the purpose of this report is to provide a broad historical review and commentary based on the views of the CES members, with particular emphasis on tracing the lengthy record of advisory committee recommendations. Any individual topic could be the subject of an extended report in its own right. Indeed, extensive further reviews are already under way to that end. If the CES has succeeded in the task it has undertaken, this report will serve as a useful starting point for any such more intensive study.
The report is divided into eight chapters: (1) an introduction, (2) the evolution of the MTPE, (3) its relationship to the USGCRP, (4) applications of earth observations data, (5) the role that smaller satellites can play in research and operational remote sensing, (6) earth system modeling and information systems, (7) a number of associated activities that contribute to the MTPE and the USGCRP, and (8) organizational issues in the conduct of civil earth observations programs. Following the body of the report is a series of appendixes: after a list of acronyms and abbreviations and collected short biographies of CES members, six brief tutorials discuss several scientific topics important to the science and applications of earth observations. Highlights from the eight chapters follow.
The NASA effort in earth observations is called the Mission to Planet Earth. It includes (1) a number of intermediate-size satellites that are collectively called the Earth Observing System (EOS); (2) a series of smaller satellites called Earth Probes; (3) a major information system named the EOS Data and Information System (EOSDIS); (4) associated research, data analysis, and mission operations activities; and (5) the Landsat-7 satellite, which will be the joint responsibility of NASA and NOAA. In addition, the MTPE relies on the availability of data from NOAA’s operational satellites, the DMSP satellites (up to the point of their merger with the NOAA polar-orbiting satellites), and numerous foreign satellites—some wholly foreign owned, others carrying NOAA or NASA instruments in cooperative ventures.