Adjacency is the radiation reflected from the neighborhood and scattered energy into the viewing direction. The effect is a result of atmospheric scattering, and depends on the reflectance contrast between a target pixel and its large-scale neighborhood, and decreases with wavelength. It reduces the apparent surface contrast by decreasing the top-of-the-atmosphere radiance over bright pixels and increasing the brightness of the dark pixels.
The adjacency effect causes a certain amount of blurring, known as crosstalk. This effect is often noticeable at the boundary of adjacent features; for example, roads passing through a forest may appear blurred. The adjacency effect is especially important for sensors of high spatial resolution, such as Rapideye and SPOT, and is usually negligible for low spatial resolution sensors such as AVHRR and Landsat.
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