冠层光谱的多项式表达模型是理解叶片／土壤系统内的光线散射过程，描述植被的冠层光谱与组分光谱间非线性关系的一种新的方法。冠层光谱的多项式表达模型用高阶多项式的形式表达了系统内的各组分对入射光的散射过程，多项式中每一项系数表达了各组分对入射光多次散射的可能性有多少，这与冠层的结构，包括作物的覆盖率、叶倾角、垄行结构等有关。因此，多项式系数具有反演冠层结构参数的潜力。本次研究首先使用SAILH模型得到玉米全生长期的BRDF波谱以及模型计算过程的中间变量冠层多角度覆盖率，建立多项式系数与多角度覆盖率之间的经验关系。最后，设计了一次野外BRDF观测试验，对经验关系进行验证。

The polynomial expression model is a new model to interpret the light scattering process inside leaf/soil system and decipher the non-linear relationship between component spectra and canopy reflectance. It uses high order polynomial to interpret the scattering process inside canopy, and each coefficient of the polynomial expression represents the possibility with which the incident light, after multi-scattering of the components, goes out of the canopy and enters the sensor. This value depends on the canopy structure including crop cover rate, leaf distribution etc. So the polynomial model has the capability to invert the canopy structural parameters. This study is designed to invert the crop cover rate using this model. Firstly the canopy reflectance model SAILH is used to simulate BRDF spectra and the corresponding cover rates. Then the relationship between the polynomial coefficients from the polynomial expression model and cover rates is built. Finally, an experiment is designed to validate the model inversion.