摘要
利用 1999年和 2 0 0 0年实测的晚稻冠层结构参数 (叶面积指数、叶倾角、叶长、叶宽等 )和叶片生物化学组分含量 (叶绿素、蛋白质、纤维素、水等 )实测数据 ,结合椭圆分布函数模型、PROSPECT模型和 FCR模型 ,模拟水稻冠层垂直反射率 ,模拟值与实测值的相关系数大于 0 .98,均方根差 RMSE小于 0 .0 5 ,从而建立了冠层结构参数、叶片生物化学组成等农学参数与冠层垂直反射率的直接联系 ,为利用物理模型反演冠层叶面积指数、叶片叶绿素含量等奠定了基础。
Measuring rice canopy structure parameters (such as leaf area index, leaf inclination, leaf length, leaf width) and leaf biochemistry contents (such as chlorophyll, protein, cellulose, water) in 1999 and 2000. Then simulate rice canopy nadir reflectance by those measured datum. The simulating models are elliptical model, PROSPECT model and FCR model. The three steps are: (1) We simulate leaf inclination distribution by elliptical model. The input parameters are model leaf inclination and eccentricity of the elliptical distribution of leaf normal which are 81 and 0 9985. The output parameter is leaf inclination distribution function. The correlations between simulated and measured are more than 0 95, and the RMSE is less than 0.03; (2) We simulate leaf reflectance and transmittance by PROSPECT model. The input parameters are leaf structural parameter and leaf chemicals (chlorophyll, protein, cellulose, etc). In the model, the leaf structural parameter equals to 1.7, while the leaf chemicals are measured datum. The correlations between simulated and measured are more than 0 95, and the RMSE is less than 0.02; (3) We simulate canopy nadir reflectance by FCR model. The parameters we need for input are optical parameters (leaf reflectance, leaf transmittance, reflectance of background on nadir view direction, refractive indices of the leaf surface wax, etc), structural parameters (leaf area index, leaf inclination distribution, relative linear size of leaves, etc) and view and illumination geometry (sun zenith angle, view zenith angle, the ratio of direct to total indices radiance). Some of the parameters are calculated in (1) and (2), some are measured, and others are valued by conference. The correlations between simulated and measured are more than 0 98, and the RMSE is less than 0.05. So, by these models, canopy structural parameters and leaf biochemistry content are directory connected to canopy reflectance. It is significant in leaf area index and chlorophyll inversion by physical model.
出处
《作物学报》
CAS
CSCD
北大核心
2003年第3期397-401,共5页
Acta Agronomica Sinica
基金
国家自然科学基金资助项目 ( 4 0 1710 65 )
国家 863资助项目 ( 2 0 0 1AA2 45 0 41)
中国博士后科学基金资助项目 ( 2 2 0 2 0 3 12 2 3 )
