Stellar scintillations in a spaceborne occultation experiment for atmospheric irregularities with the variable anisotropy
V. Kan
A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, Pyzhevsky per., 3, 119017, Moscow, Russia
Keywords: спутниковое зондирование атмосферы, переменная анизотропия неоднородностей плотности, мерцания звезд, спектры слабых мерцаний, space-borne sounding of atmosphere, variable anisotropy of density irregularities, stellar scintillations, spectra of week scintillations
Abstract
The properties of stellar scintillations are studied in occultation experiment for synchronous sounding of the atmosphere at different wavelengths. The scintillation auto- and coherence spectra are calculated for the model of three-dimensional (3D) spectrum of atmospheric irregularities with the variable anisotropy. In the calculations, we used the dependency of anisotropy coefficient on irregularity scale derived from chromatic stellar scintillation measurements by fast GOMOS (Global Ozone Monitoring by Occultation of Stars) photometers during tangential occultations. Calculations are performed in approximations of the equivalent phase screen and weak scintillations. The regime of weak scintillations for low-orbit satellites corresponds to altitudes of ray perigee above 25-30 km. A comparison of scintillation spectra for models of 3D spectrum of atmospheric irregularities with the variable and constant anisotropy is performed and joint characteristics and peculiarities are noted.
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