Analytical Jacobians of single scattering optical properties using the invariant imbedding T-matrix method

Integrated and differential optical properties of a single particle, such as the scattering, absorption, and extinction cross sections, single scattering albedo, asymmetry factor, and scattering phase matrix, are derived from electromagnetic scattering theory. This process depends on microphysical inputs which include particle shape, refractive index, aspect ratio, and size parameter. In this work, we use the invariant imbedding T-matrix method (IITM) to derive analytic expressions for Jacobians of these optical properties with respect to the input parameters. These IITM-derived Jacobians for spheroids, cylinders, and hexagonal prisms are validated by comparison with results calculated with the extended boundary condition method (EBCM) and further validated using finite-difference estimates. We examine the dependencies of these Jacobians as functions of the input microphysical parameters, focusing again on spheroids, cylinders, and hexagonal prisms. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

In this study, the integrated and differential optical properties of single particles were derived from electromagnetic scattering theory, and Jacobians of these properties with respect to input parameters were obtained using the IITM method. The validity of these Jacobians for different particle shapes was confirmed through comparisons with results calculated by the EBCM method and finite-difference estimates. The dependencies of these Jacobians on input microphysical parameters were analyzed for spheroids, cylinders, and hexagonal prisms.