CIESIN Thematic Guides

Satellite Remote Sensing and its Role in Global Change Research

From a general perspective, remote sensing is the science of acquiring and analyzing information about objects or phenomena from a distance. As humans, we are intimately familiar with remote sensing in that we rely on visual perception to provide us with much of the information about our surroundings. As sensors, however, our eyes are greatly limited by 1) sensitivity to only the visible range of electromagnetic energy; 2) viewing perspectives dictated by the location of our bodies; and 3) the inability to form a lasting record of what we view. Because of these limitations, humans have continuously sought to develop the technological means to increase our ability to see and record the physical properties of our environment.

Beginning with the early use of aerial photography, remote sensing has been recognized as a valuable tool for viewing, analyzing, characterizing, and making decisions about our environment. In the past few decades, remote sensing technology has advanced on three fronts: 1) from predominantly military uses to a variety of environmental analysis applications that relate to land, ocean, and atmosphere issues; 2) from photographic systems to sensors that convert energy from many parts of the electromagnetic spectrum to electronic signals; and 3) from aircraft to satellite platforms. Today, we define satellite remote sensing as the use of satellite-borne sensors to observe, measure, and record the electromagnetic radiation reflected or emitted by the Earth and its environment for subsequent analysis and extraction of information.

Appreciating the role of satellite remote sensing in global change research requires an understanding of the following: