Final Report Summary - SAEMPL (Scattering and absorption of electromagnetic waves in particulate media)
We have devised novel numerical methods for scattering and absorption of electromagnetic waves in discrete random media of particles. In the numerical methods, we compute the so-called ladder and cyclical interaction terms of the diagrammatic description of the problem. The computations are based on an exact treatment of scattering and absorption of a wavelength-scale volume element of the medium, as well as an exact treatment of the mutual interaction of the volume elements in the medium, accounting for the near-field effects. The numerical methods of multiple scattering have been validated, for small systems of particulate media, by exact electromagnetic methods based strictly on the Maxwell equations and, for large systems of particulate media, by experimental measurements using the acoustic-levitator-based scatterometer designed and constructed in the project. The numerical and experimental methods have been applied to the interpretation of meteorite UV-Vis-NIR laboratory spectra as well as the spectroscopy, photometry, and polarimetry of atmosphereless solar system bodies, such as asteroids.