Deserts and Vegetated Areas

Dense vegetated areas appear relatively dark in VIS imageries. Mountains with thick forests can be easily identified when sparsely vegetated plains surround it. Deserts with very sparse vegetation combined with red and yellow soils and rocks make the earth's surface highly reflective. These areas appear brightest in satellite pictures.

Surface temperature differences between deserts and vegetated regions are often modified diurnally by water vapor absorption in moist low levels of the atmosphere. Hence the radiation emitted from the surface reaches the satellite undiminished only when the atmosphere is dry. When it is moist the radiation from the high cold levels only reach and hence the IR imagery is not much influenced by the surface characteristics.

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