Statistical radiometry

Abstract

This paper reviews developments in recent research on the connections between classical radiometry and the modern theory of partial coherence. This research addresses some important questions such as, why does the classical theory appear to give correct results for electromagnetic radiation from thermal sources, and how can the theory be modified to apply to radiation from nonthermal sources? The following specific facts are explained. The far field radiation pattern from a localized source distribution generally depends on the coherence properties of the source and not simply on its emittance. Classical radiometry applies to thermal radiation not because this radiation is incoherent but rather because it is partially coherent in a particular manner. Also, some quantities defined in classical radiometry have physical meaning for an electromagnetic field, and some do not.

On the relevance of two‐dimensional models for radiation of statistical sources in stratified media

“…It should be noted that although our original interest in the relations between 2‐D and 3‐D models was motivated by analysis of optical emission of organic light‐emitting diodes [ Epstein et al , ], the results we present herein are of fundamental electromagnetic nature. Hence, they are highly relevant to a variety of radio frequency or microwave problems involving statistical sources, e.g., corona on electric power lines [ Olsen and Wu , ], lightning discharge [ Valdivia et al , ], and thermal radiation [ Carter , ]. Moreover, as the rigorously derived expressions for the radiation patterns coincide with results obtained by employing the geometrical optics (GO) approximation, this work also provides intuition regarding the possible extension of the present results to other, not necessarily planar, geometries, in which GO is applicable [ Epstein et al , ].…”

“…All Rights Reserved. lines [Olsen and Wu, 1989], lightning discharge [Valdivia et al, 1998], and thermal radiation [Carter, 1983]. Moreover, as the rigorously derived expressions for the radiation patterns coincide with results obtained by employing the geometrical optics (GO) approximation, this work also provides intuition regarding the possible extension of the present results to other, not necessarily planar, geometries, in which GO is applicable [Epstein et al, 2013].…”