Retrieval of vertical profiles of atmospheric refraction angles by inversion of optical dilution measurements

[摘要] In this paper, we consider occultations of celestial bodies through the atmospheric limbfrom low Earth orbit satellites andwe show how the usual change of tangent altitude associatedwith atmospheric refraction is inseparably connected to a variation of the observedapparent intensity, for extended and pointlike sources. We demonstrate,in the regime of weak refraction angles, that atmospheric optical dilutionand image deformation are strictly concomitant. The approach leads tothe integration of a simple differential equation related to the observedtransmittance in the absence of other absorbing molecules along theoptical path. The algorithm does not rely on the absolute knowledge of theradiometer pointing angle that is related to the accurate knowledge of the satellite attitude.We successfully applied the proposed method to the measurementsperformed by two past occultation experiments: GOMOS for stellar andORA for solar occultations. The developed algorithm (named ARID) willbe applied to the imaging of solar occultations in a forthcoming pico-satellitemission.

[学科分类] 几何与拓扑