油菜角果高光谱成熟指数构建  

Construction of rape silique ripening index based on hyperspectral characteristics

作　　者：王克晓 周蕊[1] 黄祥 虞豹[1] 李波 WANG Ke-xiao;ZHOU Rui;HUANG Xiang;YU Bao;LI Bo(Institute of Agricultural Information Science and Technology,Chongqing Academy of Agricultural Sciences,Chongqing 401329,China)

机构地区：[1]重庆市农业科学院农业科技信息研究所,重庆401329

出　　处：《江苏农业学报》2023年第3期716-723,共8页Jiangsu Journal of Agricultural Sciences

基　　金：重庆市农业科学院绩效激励引导项目(cqaas2021jxjl17);重庆市技术创新与应用发展专项(cstc2021jscx-lyzxX0001)。

摘　　要：为建立油菜角果成熟程度定量化评估指标,以不同品种、不同成熟等级的油菜角果为研究对象,在分析其非成像原始高光谱反射曲线、一阶微分变换光谱和连续统去除变换光谱的基础上,开展不同成熟等级油菜角果光谱特征差异研究,构建一种能够有效辨别油菜角果成熟程度的高光谱指数。结果表明,不同品种、不同成熟等级的油菜角果反射光谱差异较大,在625 nm两侧光谱反射率明显不同;油菜角果成熟等级越高,红光吸收谷越浅,其谷点波深越低,吸收谷反射率不断增强,红光吸收谷位置基本稳定在675 nm左右;选用625 nm、675 nm和730 nm 3个高光谱波段构建新的油菜角果成熟指数(CPMI2),与改进型叶绿素吸收比值指数(MCARI)、水波段指数(WBI)、油菜角果成熟指数(CPMI)3个光谱指数的决定系数分别为0.89、0.81和0.55,即与反映植被叶绿素含量、水分含量的光谱指数及已有的角果成熟指数有较高的相关性,与油菜角果成熟程度具有较好的一致性。本研究结果可为利用高光谱探测油菜角果成熟度,有效确定油菜适宜收获期提供参考。In order to establish a quantitative evaluation index for rape silique maturity,the hyperspectral characteristics of rape siliques with different varieties and maturity levels were analyzed by the way of non-imaging original reflection curve,the first derivative transformation and continuous removal transformation,and a hyperspectral index that could effectively distinguish the maturity was constructed.The results showed that the reflectance spectra of rape siliques with different varieties and maturity levels were significantly different,especially around 625 nm.The higher the maturity level of rape siliques,the shallower the red light absorption valley,and the lower the wave depth of its valley point.The reflectivity of the absorption valley was enhanced,but the position of the red light absorption valley was basically stable at about 675 nm.The bands of 625 nm,675 nm and 730 nm were selected to construct the canola pod maturity index-2(CPMI2).The determination coefficients of CPMI2 with modified chlorophyll absorption ratio index(MCARI),water band index(WBI)and canola pod maturity index(CPMI)were 0.89,0.81 and 0.55 respectively,indicating that CPMI2 had a high correlation with the spectral indices reflecting the chlorophyll content,water content and ripeness of pod,and had a better consistency with rape silique ripeness.The results of this study can provide a reference for the hyperspectral detection of rape silique maturity and the effective determination of the appropriate harvest time of rape.

关 键 词：油菜角果 成熟度 高光谱特征 光谱指数 

分 类 号：S127[农业科学—农业基础科学] S565.4