Numerical simulation of surface roughness impact on dust optical properties

A stochastic differential equation method is introduced for geometric modeling of dust surface roughness along with discrete differential geometry technique. Optical scattering properties are computed for randomly oriented spheroidal particles with uniformly random surface roughness. Invariant imbedding T-Matrix and geometric optics method are applied to compute light scattering properties of dust particles covering from Rayleigh to geometric optics region. We simulated optical scattering properties of feldspar with these new model particles, which shows better performance than smooth spheroids. In addition, we also introduce entropy and relative entropy as similarity measures of particle scattering properties, especially phase functions.