Infrared imaging is only one example of using wavelengths other
than visible light to gather information about Earth. Most
satellites today measure energy at many wavelengths. This is
called multispectral imaging. Images taken at different
wavelengths can be combined to make composite images by
displaying the image for each wavelength as red, green, or blue
in the final image. These composite images result in color
patterns that can be used to identify surface features. This
simulation shows images of San Francisco, California at three
different wavelengths. Bright areas show higher amounts of
energy; darker areas show lower amounts of energy. You can
display each image in red, green, or blue light, then generate a
false-color composite image for any color combination. Look for
these features in the image: Water appears dark around land in
the center of the image. Blocky patterns represent buildings and
streets. Park areas on both sides of the Golden Gate Bridge (the
thin line across the water in upper left o