A variational method to inverse the radiative transfer equation: Application to thermal sounding of atmospheres of giant planets

The purpose of this paper is to inverse the radiative transfer equation. In a optically thick and non-scattering medium this equation takes the form of a convolution type integral equation. We solve this equation by means of a variational algorithm. Thus, the constraining study of ratio signal over noise used in the classical smoothing method is suppressed. An application to the sounding of the atmosphere of giant planets with several levels of noise is finally carried out. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.