欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
开展高光谱作物生物量估算敏感波段中心和最优波段宽度筛选对提高作物生物量估算精度具有重要意义。该文以冬小麦为研究对象,利用小麦关键生育期内350～1000 nm冠层高光谱数据和实测地上鲜生物量,研究任意两波段构建的窄波段归一化植被指数N-NDVI（narrow band normalized difference vegetation index）与冬小麦地上鲜生物量间的相关关系,构建拟合精度R2二维图,并以R2极大值区域重心作为高光谱估算鲜生物量敏感波段中心。通过对敏感波段中心进行波段扩展和相应生物量估算验证,最终确定敏感波段最佳波段宽度。在此基础上,开展基于敏感波段最优波段宽度下冬小麦地上鲜生物量估算和精度验证。结果表明,在N-NDVI与冬小麦鲜生物量间拟合R2≥0.65的二维区域内,确定了401 nm/692 nm、579 nm/698 nm、732 nm/773 nm、725 nm/860 nm、727 nm/977 nm 5个鲜生物量估算的高光谱敏感波段中心;在高光谱估算生物量归一化均方根误差NRMSE≤10%、相对误差RE≤10%条件下,上述5个敏感波段中心的最优波段宽度分别为±21 nm、±5 nm、±51 nm、±40 nm和±23 nm。通过与实测鲜生物量数据对比,利用上述敏感波段中心最优波段宽度进行作物生物量估算,精度在P〈0.01水平上均达到极显著水平,且RE、NRMSE分别在8.15%～9.14%、8.69%～9.65%范围内。可见,利用作物冠层高光谱进行冬小麦地上鲜生物量估算时,N-NDVI与鲜生物量间拟合R2极大值区域重心的作物高光谱敏感波段筛选和最优波段宽度确定具有一定可行性,为开展作物高光谱数据波段优选提供了新思路,也为多光谱遥感波段设置及遥感数据应用潜力评价提供一定依据。
英文摘要：
The selection of sensitive band center and optimal band width is of great significance to improve accuracy of crop biomass estimation based on hyperspectral data. As one of main food crops, winter wheat yield is critical for food safety and winter wheat biomass is the base of crop productivity, so accurate estimation of winter wheat biomass is particularly important. Objective of the study was to determine sensitive spectral band centers and their band widths which were best suited for characterizing agricultural crop biophysical variables. The experiment data included winter wheat canopy hyperspectral reflectance data between 350 nm and 1 000 nm in critical crop growth stages and field-measured fresh crop biomass. In order to achieve above purposes, firstly linear models were established between fresh winter wheat biomass and narrow band normalized difference vegetation indexes（N-NDVI） derived from crop canopy hyperspectral reflectance. Then two-dimensional distribution of R2 values was drawn through analyzing correlations between winter wheat fresh biomass and N-NDVI of any two bands. In order to select optimal band width, area weight of R2 maximum values was regarded as the hyperspectral sensitive band-pair center because of the non-uniform of R2 distribution. After that, band widths of sensitive band centers were extended with a step length of ±1 nm（±3 nm when band width exceeded 50 nm）. Finally, the results of band extension were validated and the optimal band widths of sensitive band centers were ultimately determined at a higher accuracy level. On this basis, winter wheat fresh biomass were estimated based on the optimal band widths of sensitive band centers and the accuracy of the winter wheat biomass estimation results were validated. The results indicated that five band-pairs centered at 401 nm/692 nm, 579 nm/698 nm, 732 nm/773 nm, 725 nm/860 nm, and 727 nm/977 nm were the best combinations for fresh crop biomass estimation as the weight of an area with R2≥0.65 was selected as a sensitive ba
同期刊论文项目
同项目期刊论文
期刊信息
位置：