Analysis and validation of wave backscatter coefficients asymmetry and anisotropy at low incidence angle
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摘要: 基于北京遥测技术研究所机载波谱仪实测数据以及ECMWF提供的风场数据,分析了不同风速条件下小入射角海浪平均后向散射系数不对称性与各向异性随入射角的变化特性,并对导致这一现象的原因进行了初步分析。结果表明:小入射角下,海浪平均后向散射系数随入射角增大呈现递减趋势并在18°时达到某一稳定值,之后基本维持不变;海浪后向散射系数不对称性与各向异性均随入射角增大呈现递增趋势,同样在18°增大至某一稳定值,之后基本维持不变;低风速条件下,海浪不对称性和各向异性与风速有关,且风速越大不对称性与各向异性越明显。Abstract: Based on the China Academy of Space Technology airborne spectrometer test data and the ECMWF wind data, the average backscattering cross sections, asymmetry and anisotropy changed with the incidence angle under different wind speed conditions, and the reason of wave backscatter asymmetry and anisotropy were preliminary analyzed. The results showed that at low incidence angle, the average backscattering cross section decreased as the incidence angle increased and reached a stable value at 18°,after essentially unchanged;wave backscatter asymmetry and anisotropy increased as incidence angle increased, reached a stable value at 18°, after essentially unchanged; under small winds speed conditions, waves asymmetry and anisotropy were related with wind speed, and the anisotropy and asymmetry were more obvious as wind speed increased.
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Key words:
- airborne spectrometer /
- wave /
- low incidence angle /
- asymmetry /
- anisotropy
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