A MONTE-CARLO MODEL OF POLARIZED THERMAL EMISSION FROM PARTICULATE PLANETARY SURFACES

We model the thermal emission from a particulate planetary surface composed of randomly positioned spherical grains which are large relative to the scale of the wavelength of emission. The model includes the direct emission from individual grains and multiple scattering between particles within the regolith; diffraction and the volume (transmitted) component of the scattered radiation are ignored. Using a Monte Carlo ray tracing approach, we calculate the directional and spectral emissivity of the surface and the polarization of the emitted radiation for emission angles 0°-90° and wavelengths 7-16 μm. We separate the effects of roughness at the scale of the individual grains and scattering and show how each separately affects the emitted radiation field. The results are then discussed as applicable to relevant problems in planetary remote sensing. © 1992.