Method for soil moisture retrieval in arid prairie using TerraSAR-X data
Method for soil moisture retrieval in arid prairie using TerraSAR-X data
复制标题
利用TerraSAR-X数据反演干旱草原土壤水分的方法
DOI：
10.1117/1.jrs.9.096062
复制
发表时间：
2015-04-20
影响因子：
1.7
通讯作者：
Li, Xiaowen
中科院分区：
文献类型：
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作者：
Bai, Xiaojing;He, Binbin;Li, Xiaowen
在干旱草原上，土壤水分对草原资源管理有着重大影响。基于合成孔径雷达（SAR）的土壤水分反演常常受到植被后向散射系数的影响。提出了一种利用TerraSAR-X卫星数据反演土壤湿度的新方法。该方法包括裸土后向散射σ（o）（ppsoil）模拟，植被效应校正，以及σ（o）（ppsoil）和土壤水分之间的关系建立。采用正演积分方程模型描述裸露土壤表面。通过经验比值法消除了植被的影响。土壤湿度从估计的sigma（o）（ppsoil）中检索。利用乌图美仁草原采集的数据集对该方法进行了验证。采用四种不同的植被变量，包括叶面积指数（LAI），归一化差异植被指数，增强植被指数，植被含水量，分别分离植被的影响。当利用叶面积指数来解耦植被影响时，土壤水分反演误差最小，均方根误差达到5.02vol. %。从实验结果来看，建议用叶面积指数来表征植被的散射机制。这些结果表明，TerraSAR-X数据在干旱草原土壤水分反演业务的潜力。(C)2015年，美国光电仪器工程师学会（SPIE）
In arid prairie, soil moisture has a substantial impact on the prairie resource management. The synthetic aperture radar (SAR) based soil moisture retrieval is often hampered by vegetation effects on the backscattering coefficient. A new method has been proposed to retrieve soil moisture using TerraSAR-X data. The developed method included bare soil backscattering sigma(o)(ppsoil) simulation, vegetation effect correction, and the relationship between sigma(o)(ppsoil) and soil moisture establishment. The bare soil surface was described using the forward advanced integral equation model. The vegetation influence was eliminated through an empirical ratio method. Soil moisture was retrieved from the estimated sigma(o)(ppsoil). The collected datasets in Wutumeiren prairie were used to verify the developed method. Four different vegetation variables were incorporated to separate the influence of vegetation, including leaf area index (LAI), normalized difference vegetation index, enhanced vegetation index, and vegetation water content, respectively. The lowest soil moisture inversion error was found when LAI was applied to decouple the effect of vegetation, which led the root mean square error to reach up to 5.02 vol.%. From the perspective of experiment results, LAI was recommended to characterize the scattering mechanism of vegetation. These results indicated that TerraSAR-X data have an operational potential for soil moisture retrieval in arid prairie. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)