Linear systems methods in some problems of radiative transfer between parallel planes

In practical problems of radiative transfer the methods of linear systems theory can often be used to calculate and understand better the plane-to-plane propagation of thermal radiation and scattered noncoherent radiation. In this approach the radiation on one plane due to a small surface element on the other is thought of as a spread function, its Fourier transform being a transfer function. The radiative transfer equations can then be written in either the spatial domain or the spatial frequency domain. © 1985 Optical Society of America.