The true-color image at left is a downward-looking (nadir) view
of the eastern United States, stretching from Lake Ontario to
northern Georgia, and spanning the Appalachian Mountains. The
three images to the right are also in true-color, taken by the
forward 45.6-degree, 60.0-degree, and 70.5-degree cameras,
respectively, of the Multi-Angle Imaging Spectro-Radiometer
(MISR) instrument on NASA's Terra satellite. As the slant angle
increases, the line-of-sight through the atmosphere grows longer,
and a pall of haze over the Appalachians becomes progressively
more apparent. You can see a similar effect by scanning from
near-nadir to the horizon when standing on a mountain top or
looking out an airplane window. MISR uses this multi-angle
technique to monitor particulate pollution and to distinguish
different types of haze. These observations reveal how airborne
particles are interacting with sunlight, a measure of their
impact on Earth's climate system. The images are about 400 km
(250 miles) wide, and the spatial resolution is 1.1 kilometers
(1,200 yards). North is toward the top.
Image Credit: NASA/GSFC/JPL, MISR Science Team
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