Scattering matrices and expansion coefficients of Martian analogue palagonite particles

TL;DR

This paper measures and synthesizes scattering matrices of Martian analogue palagonite particles, enabling improved radiative transfer modeling of Martian dust by providing comprehensive scattering data and a novel method for complete angular coverage.

Contribution

The paper introduces a new method to generate a complete scattering matrix from partial measurements using spherical function expansions, facilitating accurate radiative transfer simulations.

Findings

Measured scattering matrix ratios for angles 3-174° at 632.8 nm

Developed a method to synthesize full-range scattering matrices from partial data

Provided data useful for modeling Martian atmospheric light scattering

Abstract

We present measurements of ratios of elements of the scattering matrix of Martian analogue palagonite particles for scattering angles ranging from 3 to 174 degrees and a wavelength of 632.8 nm. To facilitate the use of these measurements in radiative transfer calculations we have devised a method that enables us to obtain, from these measurements, a normalized synthetic scattering matrix covering the complete scattering angle range from 0 to 180 degrees. Our method is based on employing the coefficients of the expansions of scattering matrix elements into generalized spherical functions. The synthetic scattering matrix elements and/or the expansion coefficients obtained in this way, can be used to include multiple scattering by these irregularly shaped particles in (polarized) radiative transfer calculations, such as calculations of sunlight that is scattered in the dusty Martian atmosphere.