Using the Physical Optics Approximation for Estimating the Light Scattering Properties of Large Dust Particles for Lidar Applications

The physical optics approximation was used to solve the light scattering problem of large dust particles with irregular shape. The comparison between the physical optics approximation and the DDA method was made for particles with volume-equivalent size parameters of 44.21. A full light scattering matrix (Mueller matrix) was calculated for particles with volume-equivalent size parameters from 44 up to 220 for two wavelengths: 0.532 and 1.064 μm. The dependences of the lidar and depolarization ratio, and extinction coefficient on the number of spatial orientations of the particle were obtained. It was shown that the elements of the light backscattering matrix obey power laws.