First part of this presentation will discuss the sensitivities of radiances to surface emissivity over various surface types. Radiances simulated with different surface Bidirectional Reflection Distribution Function (BRDF) and surface emissivity models are compared. We, then will discuss the impacts of clouds and hydrometeors on radiance simulations. Methodologies shown in previous studies to parameterize scattering properties of ice clouds will be employed and comparisons will be made. Sensivities of ice cloud particle sizes, shapes, and orientations to simulated radiances for GOES-R ABI channels will be presented.