Footprints of Atmospheric Phenomena in Synthetic Aperture Radar Images of the Ocean Surface: A Review
Footprints of Atmospheric Phenomena in Synthetic Aperture Radar Images of the Ocean Surface: A Review
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DOI：
10.1007/978-94-015-9291-8_11
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发表时间：
1999
影响因子：
2.9
通讯作者：
P. Mourad
中科院分区：
文献类型：
--
作者：
P. Mourad
基于卫星的垂直极化雷达从海洋表面的后向散射测量通过经验公式转化为风速和风向。(早期文献包括Jones and Schroeder (1977), Jones et al.（1982）和Schroeder et al.（1982）。参见Stoffelen（1998）及其参考资料，了解c波段（5.3 GHz）散射计的风速和反向散射的各种“CMOD”算法。这种关系的存在是因为风通过产生重力-毛细波使水面变得粗糙（Dorman, Mollo-Christensen 1973; Kahma, Donelan 1987; Caulliez et al. 1998），这反过来又通过Bragg散射有效地反向散射雷达信号，掠角在20°到70°之间（Plant 1990）。重力-毛细波也可能是由接近破裂的风驱动的重力波锋面的皱缩产生的。（Jessup et al. 1997）回顾了有关重力毛细管波的文献，并提供了其微尺度破裂的红外图像。)在60°至10°的掠射角范围内（Plant 1997）以及较小的掠射角范围内（Smith et al. 1996），这些波可以成为直接c波段雷达反向散射的额外重要来源。它们也能引起多次散射（Trizna, Carlson 1996; Trizna 1997）。在低掠角下，由微尺度破裂产生的小尺度钻孔也是反向散射的重要来源（Trizna 1997）。皱折波是雷达反向散射的来源，与当地的短期风条件无关。风驱动的重力波和膨胀也是如此，它们调节重力-毛细波场，从而产生雷达后向散射的显著变化（Donelan, Pierson 1987）。
Measurements of satellite-based, vertically polarized radar backscatter from the ocean surface translate via empirical formulae into wind speed and direction. (Early references include Jones and Schroeder (1977), Jones et al. (1982), and Schroeder et al. (1982). See Stoffelen (1998) and its references for the various “CMOD” algorithms that relate wind speed and backscatter for C-band (5.3 GHz) scatterometers.) This relationship exists because the wind roughens the water surface via the production of gravity-capillary waves (Dorman, Mollo-Christensen 1973; Kahma, Donelan 1987; Caulliez et al. 1998) which, in turn, effectively backscatter radar signals via Bragg scattering for grazing angles between 20° and 70° (Plant 1990). Gravity-capillary waves may also be generated by the crumpling of the front of wind-driven gravity waves that are near breaking. (Jessup et al. 1997) reviews the literature on gravity capillary waves and also offers infrared images of their microscale breaking.) These waves can be an additional significant source of direct C-band radar backscatter for grazing angles between 60° and 10° (Plant 1997) as well as at smaller grazing angles (Smith et al. 1996). They can also induce multiple scattering (Trizna, Carlson 1996; Trizna 1997). Small-scale bores created by microscale breaking are also a significant source of backscatter at low grazing angles (Trizna 1997). The crumpling waves are a source of radar backscatter independent of local, short-term wind conditions. So are wind-driven gravity waves and swell, which modulate the gravity-capillary wave field, thereby producing significant variations in radar backscatter (Donelan, Pierson 1987).