摘要
通过应用一阶离散植被模型,结合前人研究成果及雷达极化特性提出了多时相多极化雷达后向散射消除农作物覆盖层影响的算法:①应用已知的假设关系将植被层的体散射用交叉极化的总散射代替;②分析并将垂直极化的总后向散射中贡献很小的植被-土壤多次散射忽略;③将直接地表的后向散射分解成土壤水分与地表粗糙度的函数,使用重轨数据消除了地表粗糙度和农作物覆盖层的影响,并使用多时相全极化L波段(频率为1.2GHz)机载雷达测量数据进行验证,成功的估算了地表土壤水分的相对变化。
In this paper, a simple discrete vegetation model is used to estimate the change of soil moisture.First, we use an assumption to replace the total volume of the backscattering from vegetation cover. Second, we ignore the double bounce com- ponent of the model of its little contribution to the whole backscattering of VV polarization; thirdly, the last term of the model, the backscattering from bare soil, is described as a function of the Fresnel reflectivity and surface roughness functions.After comparing the two repeatedly passed measurements, we get a new algorithm to estimate the relative change of soil moisture. The results show that the algorithm proposed in this paper can be used directly to estimate soil moisture change and magnitudes of the vegetated surface using multi-temporal L-band VV polarization AirSAR data.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2005年第4期596-601,共6页
Advances in Water Science
基金
中国科学院知识创新工程资助项目(CX010013)~~
关键词
极化雷达
土壤水分
植被层
相对变化
<Keyword>radar technology
soil moisture
vegetation canopy
relative change
