Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 58044 10.2205/2023ES000850 turmeq ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Microwave Radar Sensing of Sea Waves: An Effective Reflection Coefficient Microwave Radar Sensing of Sea Waves: An Effective Reflection Coefficient https://orcid.org/0000-0002-4054-4905 Караев Владимир Юрьевич Karaev Vladimir Yur'evich volody@ipfran.ru https://orcid.org/0000-0002-3795-0347 Панфилова Мария Андреевна Panfilova Mariya Andreevna https://orcid.org/0000-0001-7762-7731 Титченко Ю. А. Titchenko Yu. A. yuriy@ipfran.ru https://orcid.org/0000-0002-5353-7528 Мешков Евгений Михайлович Meshkov Evgeniy Mihaylovich https://orcid.org/0000-0002-9535-4949 Ковалдов Дмитрий Алексеевич Kovaldov Dmitry Alexeevich d.kovaldov@ipfran.ru https://orcid.org/0000-0002-4741-2999 Xiuzhong Li Xiuzhong Li https://orcid.org/0000-0002-1531-5262 Yijun He Yijun He Федеральный исследовательский центр Институт прикладной физики Российской академии наук Nizhny Novgorod RU Institute of Applied Physics Nizhny Novgorod RU Институт прикладной физики РАН Россия Institute of Applied Physics of the Russian Academy of Sciences Russian Federation School of Marine Sciences, Nanjing University of Information Science and Technology Китайская Народная Республика School of Marine Sciences, Nanjing University of Information Science and Technology China School of Marine Sciences, Nanjing University of Information Science and Technology Китайская Народная Республика School of Marine Sciences, Nanjing University of Information Science and Technology China 15 12 2023 15 12 2023 23 5 1 7 30 03 2023 06 07 2023 https://rjes.ru/en/nauka/article/58044/view

At the small incidence angles, the dominant backscattering mechanism for sea waves is the quasi-specular backscattering mechanism. The power of the reflected signal depends on the distribution function of the slopes of large-scale waves (in comparison with radar wavelength) and on the effective reflection coefficient, which is introduced instead of the Fresnel coefficient. In this paper, we discussed a new method for calculating the effective reflection coefficient from the wave scatterometer SWIM data. For the first time, measurements are performed by a radar at different azimuth angles at small incidence angles. This makes it possible to measure the effective reflection coefficient. An original algorithm was developed for data processing and determination of the total mean square slopes of large-scale sea waves and the azimuth dependence of the backscattering radar cross section at zero incidence angle. In the result of subsequent processing, the azimuth dependence of the effective reflection coefficient is retrieved. SWIM data were used to evaluate the developed algorithm. Processing of the test data set confirmed the efficiency of the algorithm. The azimuth anisotropy coefficients for the mean square slopes of large-scale waves and the effective reflection coefficient are calculated

At the small incidence angles, the dominant backscattering mechanism for sea waves is the quasi-specular backscattering mechanism. The power of the reflected signal depends on the distribution function of the slopes of large-scale waves (in comparison with radar wavelength) and on the effective reflection coefficient, which is introduced instead of the Fresnel coefficient. In this paper, we discussed a new method for calculating the effective reflection coefficient from the wave scatterometer SWIM data. For the first time, measurements are performed by a radar at different azimuth angles at small incidence angles. This makes it possible to measure the effective reflection coefficient. An original algorithm was developed for data processing and determination of the total mean square slopes of large-scale sea waves and the azimuth dependence of the backscattering radar cross section at zero incidence angle. In the result of subsequent processing, the azimuth dependence of the effective reflection coefficient is retrieved. SWIM data were used to evaluate the developed algorithm. Processing of the test data set confirmed the efficiency of the algorithm. The azimuth anisotropy coefficients for the mean square slopes of large-scale waves and the effective reflection coefficient are calculated

 microwaves small incidence angles Fresnel coefficient effective reflection coefficient microwaves small incidence angles Fresnel coefficient effective reflection coefficient The study was carried out at the expense of a grant from the Russian Science Foundation (project No. 20-77-10089).

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