Radiance Profile Enhancement for Solar Occultation Measurements

Distortions in received signals in solar occultation measurements made from space arise as a result of the systematic motion of the electro-optical sensor. In a wide range of cases, the motion-related signal distortions caused by the instrument´s full modulation transfer function are as important as those from the optics. This paper demonstrates by simulation that existing techniques in the field of digital-image processing can be applied directly to solar occultation experiments to correct for these distortions. The resulting enhanced radiation profile is much closer to the true radiance profile than is the sampled output of the instrument. Use of this enhanced radiance profile in the inversion computation should improve the retrieved atmospheric profiles considerably. It also contains a study of the accuracy of such application from the point of view of instrument noise, uncertainties in the knowledge of the instrument function, and the nature of the power spectrum of the undistorted signal.