不同时空状态下烤烟冠层光谱数据稳定性研究

Research on spectral data consistency of flue-cured tobacco canopy under different spatial and temporal condition

为明确烤烟光谱测定的最佳时空条件,以烤烟品种K326为材料,通过采集田间不同测定时间及探头高度下烤烟冠层光谱反射率并就其变异系数进行分析.结果表明：10：00～12：00时烤烟冠层光谱的变异系数均小于其他时段,稳定性较高;不同探头高度烤烟冠层反射光谱的变异系数在可见光（460～710 nm）波段表现为：探头高度1.0 m与1.5 m所测定的光谱数据稳定性差异不大,但都明显好于探头高度0.5 m所测光谱数据稳定性;近红外（760～1 650nm）波段探头高度为1.5 m时所测量的光谱数据最稳定,其次是探头高度为1.0 m时所测量的光谱数据,探头高度为0.5 m光谱数据变异系数最大,稳定性最差.因此,烤烟光谱测定最佳时空条件为探头高度1.5 m、测定时间10：00～12：00.

In order to determine the optimal spatial and temporal conditions for flue-cured tobacco spectral measuring, the data of canopy spectral reflectance and coefficient of variation in different spatial and temporal scales were analyzed using K326 as test material. The results showed that the canopy spectral reflectance variation coefficient during the time 10：00-12：00 was the lowest and the data consistency reached a fairly high level; the differences of canopy spectral reflectance consistency between probe height 1.0 m and 1.5 m in the visible band （460-710nm） were not-significant, but their data consistency were significantly better than the those with probe height 0.5m; the spectral data consistency of probe height 1.5 m were the best in near infrared band （760-1 650 nm）, followed by the spectral data of probe height 1.0 m, the spectral variation coefficient of probe height 0,5m was the highest and the data consistency was the worst. All the analysis shows that, probe height 1.5 m and the measuring time during 10：00-12：00 was the optimal spatial and temporal conditions for flue-cured tobacco spectral measuring.