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.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
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
关键词
反射光谱
时间变化
函数拟合
玉米叶片
Spectral reflectance
Temporal variation
Fitting
Maize leaf
