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Plants have distinct “color signatures,” that allow remote sensing experts to analyze reflectance patterns in the satellite images and to generate a detailed portrait of landscape vegetation--the information most useful for epidemiologists.
Using GIS, which is a spatially oriented database, the satellite image data can be combined with information from other sources, such as topographic maps or surveys. These fine-resolution images illuminate the spatial relations of landscape composition, between vegetation types, for example, or between humans and their environment. Observations of the same landscape over time provide a unique window into environmental changes like those caused by logging, dam building, or urbanization.
Not all the work is done in laboratories, though, and not all the number-crunching is done by computers. An important component of any comprehensive landscape-mapping program is what scientists call “ground truthing”: going into the field to collect data that develops and verifies the satellite-image data.
A Yale-NASA Collaboration
The National Aeronautics and Space Administration (NASA) has been combining remote sensing and infectious disease research for more than a decade, some years ago forming the Center for Health Applications of Aerospace Related Technologies (CHAART). In 1990, Dr. Fish began working with NASA on landscape epidemiology projects.
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