Emissivity as a Function of Surface Roughness: A Computer Model.

Abstract : Surface geometry plays an important role in modelling backgrounds in the infrared. In particular, surface roughness of the ocean varies as a function of wind speed, and therefore it is important to realize the impact of surface roughness on self-emissions over a wide range of wavelengths and wind speeds. This paper describes the results of a computer model used to generate a synthetic surface as a function of wind speed on the average emissivity of the given surface. Surfaces generated with varying spectral content are compared. Capillary waves are shown to have a measurable effect on the average emissivity of the ocean surface, and therefore should not be ignored when constructing a model of the ocean surface. Keywords: Emissivity; Infrared; Surface roughness; Sea surface modelling.