土壤湿度微波遥感中的植被散射模型进展

Review of Vegetation Scattering Model in Soil Moisture Microwave Remote Sensing

植被是影响土壤湿度微波遥感的主要因子之一 ,土壤湿度微波遥感的主要任务是建立含有地表土壤信息的植被散射模型。植被散射模型的建立可以加深我们对植被和土壤散射机理的理解 ,定量分析微波后向散射系数对于各散射因子的敏感性 ,进一步达到从微波信息中反演土壤湿度的目的。植被散射模型可以分为经验模型、理论模型和半经验模型 ,各种模型都具有自身的优势和局限性。经验模型的建立比较简单 ,但一般只适用于特定的研究条件 ;理论模型是建立在一定的理论基础之上 ,对于散射因子的考虑相对详尽 ,但一般模型比较复杂 ,反演相对困难 ;半经验模型是前两者的折中 ,它以植被的宏观物理参量为模型参数 ,模型的建立和反演比理论模型要简单 ,但同时也具有一定的理论依据 。

Vegetation is one of the key factors that affect the measurement of soil moisture with radar. The degree to which vegetation affects the determination of soil moisture depends on the mass of vegetation and the wavelength. The most important task of soil moisture microwave remote sensing is to develop suitable vegetation scattering models which can include the effect of soil under the vegetation. The development of these models can help us understand thoroughly the complex interaction among all scattering factors, quantitatively analyze the sensitivity of backscattering coefficient to different scattering factors, get soil moisture information by inversion. Generally, there are three different kinds of vegetation scattering models: empirical, theoretical and semi-empirical. Each kind of model has its own advantages and applicability. Reviewing the process of vegetation scattering model is beneficial to our selection of optimal model in a given research.