基于函数拟合的玉米叶片反射光谱时间变化规律分析  

Temporal Variation Analysis for Spectral Reflectance of Maize Leaves Using a Fitting Method

作　　者：瞿瑛[1,2,3] 刘素红[1,2,3] 李小文[1,2,3] 

机构地区：[1]北京师范大学地理学与遥感科学学院,北京100875 [2]北京师范大学遥感科学国家重点实验室,北京100875 [3]北京师范大学环境与数字城市北京市重点实验室,北京100875

出　　处：《光谱学与光谱分析》2013年第1期131-135,共5页Spectroscopy and Spectral Analysis

基　　金：国家高技术研究发展计划(863计划)项目(2009AA122100);国家自然科学基金项目(41171262)资助

摘　　要：为了探索玉米(Zea mays L.)叶片反射光谱时间变化规律,对21个叶位的玉米叶片进行了每天一次的反射光谱测量,获得了玉米活体叶片整个生命周期反射光谱数据1 261条。在此基础上采用光谱相关图方法,对400～960nm的可见光、近红外波段的玉米叶片反射光谱进行分段拟合,获得了7个表征玉米叶片反射光谱时间变化规律的拟合参数,并对这7个参数的时间变化趋势采用二元二次多项式进行拟合。结果表明该方法对单片叶片反射光谱的拟合效果非常理想,其中98.7%的叶片反射光谱拟合复相关系数r大于0.99,80.9%的叶片反射光谱拟合均方根误差RMSE小于0.001 5。将所有数据的拟合结果与原始数据进行比较,复相关系数r为0.9978,均方根误差RMSE为0.010 5,拟合结果表明该方法较好地保持了反射光谱时间变化的趋势,能够充分利用叶片反射光谱的相关性,有效地表征玉米叶片反射光谱随时间变化的规律。The present study is to investigate the temporal variation patterns through the dataset of spectral reflectance of maize leaf using a fitting method.In the field experiment,1 261 pieces of spectral reflectance of maize leaves at different leaf positions were measured every day during its life cycle.After signal/noise analysis,the visible and near infrared（VNIR） band（400~960 nm） was selected in this study.The spectral reflectance was fitted using a spectral scatter diagram（SSD） method.Seven fitting coefficients were employed to denote the temporal variation patterns of maize leaf,which can also be fitted by bi-variate quadratic functions.The comparison of the fitted results with the original measurement data shows that the fitting results are reasonably good,where for 98.7% leaves r is larger than 0.99,and for 80.9% leaves RMSE is less than 0.001 5.All the fitted spectral reflectance is compared with the original measurement data,where r is 0.997 8,and RMSE is 0.0105.The results show that this method is particularly suitable for presenting the temporal variation patterns of the spectral reflectance of maize leaves.

关 键 词：反射光谱 时间变化 函数拟合 玉米叶片 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]