降雨对SAR风场反演的影响及校正

发布时间：2018-01-04 03:31

  本文关键词：降雨对SAR风场反演的影响及校正　出处：《海洋学报》2017年09期 　论文类型：期刊论文

  更多相关文章： SAR 风场反演 降雨影响 校正

【摘要】：合成孔径雷达(Synthetic Aperture Radar,SAR)在风场反演中发挥着重要的作用,但由于受到降雨的影响,海面风场的反演精度会随之下降。本文利用Radarsat-2SAR观测数据,准同步降雨数据和再分析风场资料对2014年台风"威马逊"外围风场受降雨影响的情况进行了分析,建立了雨致海表阻尼后向散射系数受降雨强度,入射角等因素影响的拟合模型,并对降雨引起的信号衰减,后向体散射进行了评估。实验发现雨致海表面阻尼作用抑制风致海面波的影响十分明显,且降雨造成的信号衰减随降雨强度和入射角的增大而增加,雨滴产生的后向体散射和雨致海表阻尼作用造成的后向散射系数变化随降雨强度的增大而增加,随入射角的增大而减小。实例表明本文建立的模型能够有效改善降雨条件下SAR风场的反演精度。
[Abstract]:Synthetic Aperture radar (SAR) plays an important role in wind field inversion, but it is affected by rainfall. The inversion accuracy of the sea surface wind field will decrease with it. In this paper, the Radarsat-2SAR data are used. The quasi-synchronous rainfall data and reanalysis wind field data are used to analyze the influence of rain on the wind field around Typhoon Weimason in 2014. The rainfall intensity is established for the backscattering coefficient of rain induced sea surface damping. The fitting model of incident angle and other factors are used to evaluate the signal attenuation and backward volume scattering caused by rainfall. It is found that the influence of rain induced sea surface damping on wind-induced sea surface waves is very obvious. The signal attenuation caused by rainfall increases with the increase of rainfall intensity and incidence angle, and the change of backscattering coefficient caused by raindrop backward scattering and rain-induced sea surface damping increases with the increase of rainfall intensity. The example shows that the proposed model can effectively improve the inversion accuracy of SAR wind field under rainfall conditions.
【作者单位】： 浙江大学海洋学院;国家海洋局第二海洋研究所卫星海洋环境动力学国家重点实验室;
【基金】：国家自然科学基金(41321004,41306191,41306192,41406203,41676167) 国家863项目(2013AA09A505) 中国科技部-欧洲空间局合作“龙计划”四期项目(32249) 全球变化与海气相互作用专项国际合作项目(GASI-IPOVAI-04)
【分类号】：P714.2
【正文快照】： 杭州310012)1引言海面风场是海气相互作用研究中非常重要的参数,而台风作为天气尺度上最为强烈的海气相互作用之一,其风场信息也成为最难监测的物理量之一。传统的观测手段包括浮标、海洋站、不定期的船舶报告等,效率低、成本高,所获数据往往是零星分布的点数据,在时间和空间，

本文编号：1376849