Scattering Corrections To Extinction Coefficients Measured In Falling Snow

A method is presented for extracting extinction coefficients from transmittance measurements in a scattering atmosphere. Computation of unscattered, first-order scattered, and second-order scattered contributions to received power are calculated by using the phase function of the scattering particles and the optical characteristics of the measuring system. The method has been applied to measurements at 0.6328 and 8 to 12 micrometers made in a falling snow consisting mainly of needle-type crystals 1.5 mm in length and 100 micrometers radius. The resulting extinction coefficients at the two wave-lengths were found to be equal.