Optical Characteristics Of Windblown Dust

Naturally occurring or windblown dust causes periods of low visibility, particularly in arid regions, and can be a source of obscuration of electro-optical devices operating in the visible or infrared spectral regions. Occurrence of windblown dust and factors influencing the injection of soil into the atmosphere by the wind are described. Characteristics of the dust affecting atmospheric optical properties discussed include particle number density, particle size distributions, and complex index of refraction. The ways that variations of these characteristics affect the transmission of visible and infrared energy are described.