棉花叶片厚度的高光谱测试方法

植物叶片厚度的变化能够指示植物生长状态的改变，为了实时、活体、无损地获取叶片厚度，该研究以棉花叶片为研究对象，利用DPS、Origin统计分析软件分析84组光谱数据与叶片厚度的相关性。研究表明，光谱反射率与叶片厚度在可见光350～369 nm及664～689 nm 2个较窄区域达到了极显著正相关关系，在红外917～1 884、2 048～2 380 nm 2个区域呈极显著负相关关系，总体相关程度红外波段高于可见光波段。红边参数与叶片厚度的相关性不高，24个形状参数与厚度达到了极显著相关水平，其中，中心为980 nm的吸收谷面积与叶片厚度相关度最高，相关系数为0.848。分别用反射率、植被指数、光谱形状参数建立并测试3个估算模型，相对误差最高为7.4%，均方根差最高为0.051 mm。结果表明利用高光谱分析技术，可以实现叶片厚度的快速、活体测量。

Measurement of cotton leaf thickness with hyper spectrum

Changes of leaf thickness can indicate the variations of plant growth state, in order to carry out real-time, live, non-destructive testing of leaf thickness, the study took cotton leaves as the research object. The correlation between plant leaf spectrum and thickness was studied on 84 couples of data of cotton, with DPS and Origin statistical softwares. Studies showed that the correlation between reflectance and leaf thickness showed significantly positive relationship in two visible light regions of 350-369 nm and 664-689 nm, and significantly negative relationship in two infrared regions of 917-1 884 nm and 2 048-2 380 nm. In general, the correlation degree between reflectance and leaf thickness in infrared light was higher than that in visible light. Red edge indices showed low correlation with leaf thickness, however 24 figure indices had significant correlation with leaf thickness, and the area of absorbtion with the center of 980nm had the highest correlation degree with correlation coefficient 0.848. Three models about leaf thickness were set and tested with reflectance, plant index and spectral figure index. Among these models, the highest relative error was 7.4%, and the RMSE was 0.051 mm. It is feasible to measure alive leaf thickness untouchably with hyper spectrum.