合成孔径雷达土壤水分反演研究进展  

Progress on monitoring soil moisture using SAR data

作　　者：李俐[1] 王荻[1] 王鹏新[1] 黄健熙[1] 朱德海[1] 

机构地区：[1]中国农业大学信息与电气工程学院,北京100083

出　　处：《资源科学》2015年第10期1929-1940,共12页Resources Science

基　　金：国家自然科学基金项目(41201340)

摘　　要：土壤水分作为地表水存储的重要组成部分,直接影响着陆地和大气间的物质和能量交换,成为水文、气象、农业和生态环境等领域的研究热点之一。合成孔径雷达(Synthetic Aperture Radar,SAR)由于其数据的极化特征、后向散射强度及相位特性对土壤水分的敏感性而成为高空间分辨率土壤水分监测中最有效的方法之一。本文首先对可用于土壤水分反演的SAR传感器进行总结;然后,分别对裸露地表和植被覆盖地表的微波散射模型进行介绍;在讨论影响土壤水分监测因素的基础上,分析主要影响因素的校正方法,并探讨当前合成孔径雷达反演土壤水分的主要方法;最后总结土壤水分反演中存在的问题,同时对未来的发展方向进行展望。Soil water is an important component of surface water storage,and has a direct impact on materials and energy exchange between earth and atmosphere. Soil moisture estimation has been a research hotspot in hydrology,meteorology,agriculture and ecological environment studies. Because of the sensitivity of polarization characteristics,backscatter intensity and phase characteristics to soil moisture,Synthetic Aperture Radar（SAR）has demonstrated the potential to map and monitor relative soil moisture changes over field-scale areas with high spatial resolution.However,available SAR data and models once limited its use. Fortunately,with the development of SAR sensors,more and more data are and will be available. Here,SAR sensors are introduced and the trend of sensor development is analyzed. Technical advances such as high resolution,multi-band,multi-polarization,multi-angle,multi-mode radar and forthcoming SAR constellations will enrich the information of backscatter signals and greatly enhance the ability of SAR with respect to soil moisture estimation. Theoretical, empirical and semi-empirical microwave scattering models have been established. Commonly used backscattering models are summarized for random rough surface of bare soil and vegetation cover soil respectively. The effects of radar parameters,soil surface condition and vegetation will confound the retrieval of soil moisture from SAR,and limit applications of SAR as an operational source of soil moisture in spite of its well-known benefits of high-resolution distributed soil moisture. Following a discussion of the influencing factors for soil moisture retrieval,a discussion of parameter selections and correction for soil roughness and vegetation effects is presented. We then review state-of-the-art of SAR soil moisture retrieval methodology. A discussion of problems and trends of soil moisture retrieval is conducted to direct future research.

关 键 词：土壤水分 合成孔径雷达 模型 方法 反演进展 

分 类 号：TN958[电子电信—信号与信息处理]