Linearization of radiative transfer with respect to surface properties

The linearization of radiative transfer with respect to surface properties in the UV and visible part of the solar spectrum is presented. The proposed method is a rigorous extension of the radiative perturbation theory with r espect to surface properties. Given the forward and adjoint intensity field , analytical expressions are provided for the linearization of any observab le related to the radiation field with respect to surface properties charac terized by Minnaert's and Lambertian bidirectional reflection distribution function. For the considered surface reflection characteristics, we also di scuss an extension of the reduction approach of Chandrasekhar as an alterna tive linearization method. The suitability of both approaches for the combi ned retrieval of trace gas and surface properties from the backscattered su nlight in the UV and visible part of the spectrum is discussed. The authors come to the conclusion that the perturbation theory, for this purpose, rep resents the superior method because of its general applicability to any par ameter characterizing the optical properties of the atmosphere and the unde rlying surface. (C) 2001 Elsevier Science Ltd. All rights reserved.