Limb-viewing hyperspectral image simulation based on a polygonal earth cross-section (PEX) model

This paper will discuss recent improvements made to the Monte Carlo Scene (MCScene) code to enable limb-viewing scenarios and situations where the sun is below the horizon. MCScene is a high-fidelity model for full optical spectrum (UV through LWIR) hyperspectral image (HSI) simulation. MCScene generates HSI scenes for algorithm validation, utilizing a Direct Simulation Monte Carlo (DSMC) approach for modeling 3D atmospheric radiative transfer (RT). MCScene includes treatment of molecular absorption, Rayleigh scattering, aerosol absorption and scattering, multiple scattering and adjacency effects, as well as scattering off spatially inhomogeneous surfaces described by bidirectional reflectance distribution functions (BRDFs). The algorithm models land and ocean surfaces, 3D terrain, 3D surface objects, and effects of realistic finite clouds with shadowing. This paper will provide a brief overview of RT elements incorporated into the Monte Carlo engine and the recent addition of a polygonal earth cross-section (PEX) method for modeling.