Inversion of optical scattering and spectral extinction measurements to recover aerosol size spectra

Aerosols interact with optical radiation in a complicated way, but in a way that can be described through the methods of electromagnetic theory. By applying constrained linear inversion methods one can recover an estimate for the size spectrum of aerosols in the micron and submicron size range from measured optical data. The amount of information that can be secured is increased by combining measurements of spectral extinction with measurements of optical scattering. From the combined measurements one can obtain about seven pieces of information about the particle size spectrum, provided optical parameters are measured to 2.5% accuracy. The application of linear constrained inversion on simulated noise-degraded data successfully recovers major features, such as the presence of modes, in the aerosol size distribution function.