Radiative Properties of Real Surfaces

Abstract

In this chapter, definitions of all radiative properties that are relevant for real opaque surfaces, namely emittance, reflectance, absorptance, and transmittance, are presented. Electromagnetic wave theory is then applied to predict trends of radiative properties for metals and for dielectrics (electrical nonconductors). These theoretical results are compared with a limited number of experimental data. This is followed by a brief discussion of phenomena that cannot be predicted by electromagnetic wave theory, such as effects of surface roughness, of surface oxidation and contamination, and the preparation of “special surfaces,” i.e., surfaces whose properties are customized through surface coatings, controlled roughness, and geometric pattering. The radiative properties of the Earth's surface and their implications on climate change are also discussed. The chapter concludes with a discussion of experimental techniques that are often used to measure radiative surface properties.