Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2018, Vol. 15, No. 2, pp. 29-41
Ground radiometric measurements of the sea surface effective emissivity without absolute calibration
V.V. Sterlyadkin
1, 2 , D.S. Sazonov
2 , А.V. Kuzmin
2 , E.A. Sharkov
2 1 Moscow University of Technology, Moscow, Russia
2 Space Research Institute RAS, Moscow, Russia
Accepted: 21.03.2018
DOI: 10.21046/2070-7401-2018-15-2-29-41
Theoretical substantiation of a new method for measuring the emissivity of a rough underlying surface without absolute calibration of the radiometer is carried out. In this case, a sufficient condition for measurements is recording of the signal from the blackbody with the temperature of the underlying surface. The method is based on the measurement of the descending radiation of the atmosphere, as well as measuring the radiation coming from the underlying surface at the same zenith angle. The method makes it possible to study, for all radiation parameters, the dependences of the effective emissivity of the surface Eeff, both on the parameters of the underlying surface itself and on the parameters of the atmosphere, which are recorded at the measurement site. The values of Eeff measured in this way harmonically correspond to the radiative transfer model and directly enter into the radiation transfer equations, therefore they can be used directly for solving inverse problems. The method can be applied not only to the surface of the ocean, but also to any rough surface, ice, agricultural plantations, vegetation. The paper presents the data of field measurements performed from the offshore platform of the Black Sea Hydrophysical Polygon of the Russian Academy of Sciences. Experimentally obtained dependences Eeff on the angles of incidence and on the velocity of the surface wind obtained at the frequency of 37.5 GHz are presented.
Keywords: remote sensing of the Earth, radiometric measurements, emissivity, underlying surface, roughed ocean surface, inverse problems
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