Investigation on Doppler Shift and Bandwidth of Backscattered Echoes From a Composite Sea Surface
Investigation on Doppler Shift and Bandwidth of Backscattered Echoes From a Composite Sea Surface
复制标题
复合海面后向散射回波的多普勒频移和带宽研究
DOI：
10.1109/tgrs.2010.2070071
复制
发表时间：
2011-03
影响因子：
8.2
通讯作者：
Zhang, Yanmin
中科院分区：
文献类型：
--
作者：
Wang, Yunhua;Zhang, Yanmin
在二阶小斜率近似(SSA-II)的一般框架下，预测了小角度和中等入射角下时变海面后向散射场的多普勒频移。复合海面被模拟为大尺度重力波和小尺度波纹的叠加。这里，每个小面片在一级近似条件下沿闭合轨道运动的大尺度表面分量的标高由小面片的坐标来描述。将预测的多普勒频移与小摄动法(SPM)、几何光学方法、一阶SSA-I(SSA-I)和双尺度散射法(TSM)的结果进行了比较。我们可以发现，共振态下SPM和SSA-I的预测多普勒频移对偏振态不敏感。然而，SSA-II得到的结果与TSM得到的结果是一致的，并且在HH和VV极化之间产生了显著的差异。光谱带宽主要由海面轨道运动引起。本文还在TSM的基础上，推导了复合海面散射回波的频谱带宽公式。将预测的带宽与蒙特卡罗模拟结果和测量数据进行了比较。此外，还讨论了多普勒频移和带宽与极化、风速、雷达频率等参数的关系。
In the general framework of the second-order small-slope approximation (SSA) (SSA-II), Doppler shifts of backscattered fields from time-varying sea surfaces are predicted at small and moderate incidence angles. The composite sea surface is modeled as a superposition of large-scale gravity waves and small-scale ripples. Here, the elevation of the large-scale surface component, on which each small facet travels along a closed orbit under the condition of the first-order approximation, is described by the coordinates of the small facets. The predicted Doppler shifts are compared with the results obtained by the small perturbation method (SPM), the geometrical optics method, the first-order SSA (SSA-I), and the two-scale scattering method (TSM). We can find that the predicted Doppler shifts for SPM and SSA-I in copolarized configuration are insensitive to the polarization state. However, the results obtained by SSA-II are consistent with those obtained by TSM and yield significant differences between HH and VV polarizations. Spectrum bandwidth is mainly induced by sea-surface orbit motions. In this paper, the formula of the spectrum bandwidth for the scattered echoes from the composite sea surface is also derived on the basis of TSM. The predicted bandwidths are compared with the Monte Carlo simulated results and the measured data. Furthermore, the dependences of the Doppler shift and the bandwidth on the parameters, such as the polarization, wind speed, radar frequency, etc., are also discussed.
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影响因子：
3.4
作者：
J. Robertson
通讯作者：
J. Robertson
DOI：
10.1109/tgrs.2003.814662
发表时间：
2003-10
期刊：
IEEE Trans. Geosci. Remote. Sens.
影响因子：
--
作者：
Alfonso R. Hayslip;J. Johnson;G. Baker
通讯作者：
Alfonso R. Hayslip;J. Johnson;G. Baker
DOI：
--
发表时间：
1982-08
期刊：
--
影响因子：
--
作者：
F. Ulaby;R. Moore;A. Fung
通讯作者：
F. Ulaby;R. Moore;A. Fung
影响因子：
8.2
作者：
G. Soriano;M. Joelson;M. Saillard
通讯作者：
G. Soriano;M. Joelson;M. Saillard
DOI：
--
发表时间：
1972
期刊：
--
影响因子：
--
作者：
V. Derr
通讯作者：
V. Derr