A Model of Radar Backscatter of Rain-Generated Stalks on the Ocean Surface
A Model of Radar Backscatter of Rain-Generated Stalks on the Ocean Surface
复制标题
DOI：
10.1109/tgrs.2016.2614897
复制
发表时间：
2017-02
影响因子：
8.2
通讯作者：
Xinan Liu;Q. Zheng;Ren Liu;M. Sletten;J. Duncan
中科院分区：
文献类型：
--
作者：
Xinan Liu;Q. Zheng;Ren Liu;M. Sletten;J. Duncan
本文提出了一个雨场中海面雨生柄的雷达后向散射模型。在模型中，秸秆在雨场中形成阵列，并被认为是一个无限的水面站在有限的水柱。推导了这些秸秆的雷达后向散射系数。考虑了秸秆的非相干和相干后向散射机制。该模型表明，雷达后向散射强度是水面上的平均间距、雷达波频率和雷达波入射角的函数。对于小/中雨（在低降雨率），雷达后向散射强度随降雨率的增加而增加。对于大雨（在高降雨率），雷达后向散射强度随降雨率的增加而减小。最大雷达后向散射强度出现在降雨率，这取决于雷达波的频率和雷达波的入射角。本模式被用来解释雷达信号的降雨事件同时观察到的C-波段ENVISAT（欧洲卫星）高级合成孔径雷达（ASAR）和地基天气雷达在西北太平洋。从C波段ASAR图像提取的雷达回波强度与地基天气雷达得到的降雨率之间的关系与模型计算结果一致。在实验室条件下研究了雨场中的海气界面及其对雷达后向散射衰减的影响。
In this paper, a model of radar backscattering from rain-generated stalks on the ocean surface in a rain field is proposed. In the model, stalks in the rain field form an array and are considered as finite water cylinders standing out of an infinite water surface. The radar backscattering coefficient from these stalks is derived. Both incoherent and coherent backscattering mechanisms from the stalks are considered. The model shows that the radar backscattering intensity is a function of the average distance between stalks on the water surface, the radar wave frequency, and the incident angle of radar waves. For light/moderate rain (at low rain rates), the radar backscattering intensity increases with increasing rain rate. For heavy rain (at high rain rates), the radar backscattering intensity decreases with increasing rain rate. The maximum radar backscattering intensity occurs at a rain rate that depends on the radar wave frequency and the incident angle of radar waves. The present model is used to explain the radar signatures of a rainfall event simultaneously observed by C-band ENVISAT (European satellite) Advanced Synthetic Aperture Radar (ASAR) and ground-based weather radar in the Northwest Pacific. The relationship between the radar return intensity extracted from the C-band ASAR image and the rain rate obtained from ground-based weather radar is in agreement with the model’s calculation. Also, the air–sea interface in rain fields and its effects on the attenuation of radar backscattering are experimentally studied in the laboratory.