Multiple scattering spectra through fog particles in the ellipsoidal model
椭球模型下通过雾场的多重光散射谱

Because of the properties of non-sphericity and multiple scattering of fog particles and the effects of geometrical optics,the light scattering through fog has become a difficult problem.In this paper,we establish an ellipsoidal model of fog particles.On the basis of radiative-transfer equation and with the consideration of the effects of geometrical optics,we obtain a formula of calculating multiple light scattering intensity through the fog particles with different sizes and different shape distributions.Our results are in agreement with the earlier results in two special cases,which verifies that our method is reliable.The calculations show that scattering spectra through the ellipsoidal fog particles present elliptical feature,which is different from circular feature for random orientation non-spherical particles.At the different orientation angles the angular distributions of the light intensity are different,and this difference becomes smaller with the shape ratio approaching to 1.The stripes of the scattering spectra progressively disappear with the increase of optical thickness,which is different from the case of single-scattering.At different orientation angles and observation angles,the scattering intensities always first increase then decrease with the increase of optical thickness for the fog particles of the different size distributions and different shape ratio distributions,and a maximal intensity occurs at t = 1.0—3.0.The calculations also indicate that the scattering spectra of actual fog particles present the turbid pattern around the central light speckle because of wide size distribution in many cases.