ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa


Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2016, Vol. 13, No. 6, pp. 119-134

The use of the sea buoys data for estimating the variance of slopes of large-scale waves for Ku- and Ka-bands

M.A. Panfilova 1 , V.Yu. Karaev 1 
1 Institute of Applied Physics RAS, Nizhny Novgorod, Russia
Accepted: 30.11.2016
DOI: 10.21046/2070-7401-2016-13-6-119-134
The variance of sea surface slopes of a larger scale compared to the probing wave length is an important parameter which influences backscattering of microwaves by the sea surface as well as air-sea interaction. In the present work, the dependence of the variance of slopes on parameters measured by sea buoys is investigated. The contribution of each parameter to the variance of slopes is evaluated. For this purpose a database which includes the dual frequency precipitation radar data (normalized radar backscattering cross section (NRCS) for Ku- and Ka-bands, the incidence angles) and sea buoys data (sea waves parameters and parameters characterizing the near surface atmosphere layer) was created. The collocation window by time between radar and buoys measurements is 30 minutes and collocation window by space is 40 km. The data of the precipitation radar were used to estimate the slope variance of the sea surface along the scanning direction and NRCS at zero incidence angle. The algorithm to calculate the total slope variance from the NRCS at zero incidence angle was suggested. The total slope variance which is retrieved from the precipitation radar data was considered as a reference value in the present research. The empirical dependence of the total slope variance for Ku- and Ka-bands on the parameters measured by sea buoys (significant wave height, dominant and average periods of wave spectrum, the water and air temperature, wind and wave directions and wind speed) was obtained.
Keywords: sea buoys, microwave remote sensing of the sea surface, low incidence angles, slope variance
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