In this study, a method was presented to accurately obtain the extinction characteristics of non-spherical biological particle aggregates. Based on multi-sphere model particles, randomly oriented aggregation firstly built construct The discrete-dipole approximation used calculate aggregates in 3–14 µm waveband. average mass coefficients three materials are 0.802 m2/g, 0.907 and 0.866 m2/g 3–5 w...