Derivation of aerosol size distribution with a bistatic system using a multi-wavelength laser

The estimation of aerosol size distributions from measurements of scattered light intensity with a bistatic system using a multi-wavelength laser is presented. A singular value decomposition(SVD) was applied to the inversion to infer the size distribution from the scattered Light intensity. In the physical experiment, a scattering angle of 160 degree was selected because of the limitations of apparatus configuration. Five kinds of polystyrene latex particles(PSL) with a size range of particle radii from 0.25 to 2.7 mu m were selected as sample particles and dispersed in water. These sols were mixed and two types of model sols were prepared. The size distribution of one sol was a Junge type and that of the other, a log-normal type. These sols were supplied to the aerosol generator based on the spray-dry method, and the sample aerosol was dispersed from the nozzle into the air. The scattered light intensity from these artificial PSL aerosol were measured at five wavelength. The size distributions were inferred successfully from the inversion of scattered light intensity by SVD.