CALCULATION OF THE T-MATRIX AND THE SCATTERING MATRIX FOR ENSEMBLES OF SPHERES

We present a method for determination of the random-orientation polari metric scattering properties of an arbitrary, nonsymmetric cluster of spheres. The method is based on calculation of the cluster T matrix, f rom which the orientation-averaged scattering matrix and total cross s ections can be analytically obtained. An efficient numerical method is developed for the T-matrix calculation, which is faster and requires less computer memory than the alternative approach based on matrix inv ersion. The method also allows calculation of the random-orientation s cattering properties of a cluster in a fraction of the time required f or numerical quadrature. Numerical results for the random-orientation scattering matrix are presented for sphere ensembles in the form of de nsely packed clusters and linear chains. (C) 1996 Optical Society of A merica.